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- Lines: 2859
- Date:
Thu Oct 14 14:22:08 1999
- Orig file:
v2.3.21/linux/Documentation/filesystems/proc.txt
- Orig date:
Mon Oct 4 15:49:29 1999
diff -u --recursive --new-file v2.3.21/linux/Documentation/filesystems/proc.txt linux/Documentation/filesystems/proc.txt
@@ -1,1379 +1,1714 @@
+------------------------------------------------------------------------------
+ T H E /proc F I L E S Y S T E M
+------------------------------------------------------------------------------
+/proc/sys Terrehon Bowden <terrehon@pacbell.net> October 7 1999
+ Bodo Bauer <bb@ricochet.net>
+------------------------------------------------------------------------------
+Version 1.2 Kernel version 2.2.12
+------------------------------------------------------------------------------
+
+Table of Contents
+-----------------
+
+ 0 Preface
+ 0.1 Introduction/Credits
+ 0.2 Legal Stuff
+
+ 1 Collecting System Information
+ 1.1 Process-Specific Subdirectories
+ 1.2 Kernel data
+ 1.3 IDE devices in /proc/ide
+ 1.4 Networking info in /proc/net
+ 1.5 SCSI info
+ 1.6 Parallel port info in /proc/parport
+ 1.7 TTY info in /proc/tty
+
+ 2 Modifying System Parameters
+ 2.1 /proc/sys/fs - File system data
+ 2.2 /proc/sys/fs/binfmt_misc - Miscellaneous binary formats
+ 2.3 /proc/sys/kernel - general kernel parameters
+ 2.4 /proc/sys/vm - The virtual memory subsystem
+ 2.5 /proc/sys/dev - Device specific parameters
+ 2.6 /proc/sys/sunrpc - Remote procedure calls
+ 2.7 /proc/sys/net - Networking stuff
+ 2.8 /proc/sys/net/ipv4 - IPV4 settings
+ 2.9 Appletalk
+ 2.10 IPX
+
+------------------------------------------------------------------------------
+Preface
+------------------------------------------------------------------------------
+
+0.1 Introduction/Credits
+------------------------
+
+This documentation is part of a soon (or so we hope) to be released book on
+the SuSE Linux distribution. As there is no complete documentation for the
+/proc file system and we've used many freely available sources to write these
+chapters, it seems only fair to give the work back to the Linux community.
+This work is based on the 2.2.* kernel version. I'm afraid it's still far from
+complete, but we hope it will be useful. As far as we know, it is the first
+'all-in-one' document about the /proc file system. It is focused on the Intel
+x86 hardware, so if you are looking for PPC, ARM, SPARC, APX, etc., features,
+you probably won't find what you are looking for. It also only covers IPv4
+networking, not IPv6 nor other protocols - sorry. But additions and patches
+are welcome and will be added to this document if you mail them to Bodo.
+
+We'd like to thank Alan Cox, Rik van Riel, and Alexey Kuznetsov and a lot of
+other people for help compiling this documentation. We'd also like to extend a
+special thank you to Andi Kleen for documentation, which we relied on heavily
+to create this document, as well as the additional information he provided.
+Thanks to everybody else who contributed source or docs to the Linux kernel
+and helped create a great piece of software... :)
+
+If you have any comments, corrections or additions, please don't hesitate to
+contact Bodo Bauer at bb@ricochet.net. We'll be happy to add them to this
+document.
+
+The latest version of this document is available online at
+http://skaro.nightcrawler.com/~bb/Docs/Proc as HTML version.
+
+0.2 Legal Stuff
+---------------
+
+We don't guarantee the correctness of this document, and if you come to us
+complaining about how you screwed up your system because of incorrect
+documentation, we won't feel responsible...
+
+------------------------------------------------------------------------------
+CHAPTER 1: COLLECTING SYSTEM INFORMATION
+------------------------------------------------------------------------------
+
+------------------------------------------------------------------------------
+In This Chapter
+------------------------------------------------------------------------------
+* Investigating the properties of the pseudo file system /proc and its
+ ability to provide information on the running Linux system
+* Examining /proc's structure
+* Uncovering various information about the kernel and the processes running
+ on the system
+------------------------------------------------------------------------------
+
+
+The proc file system acts as an interface to internal data structures in the
+kernel. It can be used to obtain information about the system and to change
+certain kernel parameters at runtime.
+
+First, we'll take a look at the read-only parts of /proc. In Chapter 2, we
+show you how you can use /proc/sys to change settings.
+
+1.1 Process-Specific Subdirectories
+-----------------------------------
+
+The directory /proc contains (among other things) one subdirectory for each
+process running on the system, which is named after the process ID (PID).
+
+The link self points to the process reading the file system. Each process
+subdirectory has the entries listed in Table 1-1.
+
+
+Table 1-1: Process specific entries in /proc
+..............................................................................
+ File Content
+ cmdline Command line arguments
+ environ Values of environment variables
+ fd Directory, which contains all file descriptors
+ mem Memory held by this process
+ stat Process status
+ status Process status in human readable form
+ cwd Link to the current working directory
+ exe Link to the executable of this process
+ maps Memory maps
+ root Link to the root directory of this process
+ statm Process memory status information
+..............................................................................
+
+For example, to get the status information of a process, all you have to do is
+read the file /proc/PID/status:
+
+ >cat /proc/self/status
+ Name: cat
+ State: R (running)
+ Pid: 5452
+ PPid: 743
+ Uid: 501 501 501 501
+ Gid: 100 100 100 100
+ Groups: 100 14 16
+ VmSize: 1112 kB
+ VmLck: 0 kB
+ VmRSS: 348 kB
+ VmData: 24 kB
+ VmStk: 12 kB
+ VmExe: 8 kB
+ VmLib: 1044 kB
+ SigPnd: 0000000000000000
+ SigBlk: 0000000000000000
+ SigIgn: 0000000000000000
+ SigCgt: 0000000000000000
+ CapInh: 00000000fffffeff
+ CapPrm: 0000000000000000
+ CapEff: 0000000000000000
+
+
+This shows you nearly the same information you would get if you viewed it with
+the ps command. In fact, ps uses the proc file system to obtain its
+information. The statm file contains more detailed information about the
+process memory usage. Its seven fields are explained in Table 1-2.
+
+
+Table 1-2: Contents of the statm files
+..............................................................................
+ File Content
+ size total program size
+ resident size of memory portions
+ shared number of pages that are shared
+ trs number of pages that are 'code'
+ drs number of pages of data/stack
+ lrs number of pages of library
+ dt number of dirty pages
+..............................................................................
+
+1.2 Kernel data
+---------------
+
+Similar to the process entries, the kernel data files give information about
+the running kernel. The files used to obtain this information are contained in
+/proc and are listed in Table 1-3. Not all of these will be present in your
+system. It depends on the kernel configuration and the loaded modules, which
+files are there, and which are missing.
+
+Table 1-3: Kernel info in /proc
+..............................................................................
+ File Content
+ apm Advanced power management info
+ bus Directory containing bus specific information
+ cmdline Kernel command line
+ cpuinfo Info about the CPU
+ devices Available devices (block and character)
+ dma Used DMS channels
+ filesystems Supported filesystems
+ ide Directory containing info about the IDE subsystem
+ interrupts Interrupt usage
+ ioports I/O port usage
+ kcore Kernel core image
+ kmsg Kernel messages
+ ksyms Kernel symbol table
+ loadavg Load average
+ locks Kernel locks
+ meminfo Memory info
+ misc Miscellaneous
+ modules List of loaded modules
+ mounts Mounted filesystems
+ net Networking info (see text)
+ partitions Table of partitions known to the system
+ rtc Real time clock
+ scsi SCSI info (see text)
+ slabinfo Slab pool info
+ stat Overall statistics
+ swaps Swap space utilization
+ sys See chapter 2
+ uptime System uptime
+ version Kernel version
+..............................................................................
+
+You can, for example, check which interrupts are currently in use and what
+they are used for by looking in the file /proc/interrupts:
+
+ > cat /proc/interrupts
+ CPU0
+ 0: 8728810 XT-PIC timer
+ 1: 895 XT-PIC keyboard
+ 2: 0 XT-PIC cascade
+ 3: 531695 XT-PIC aha152x
+ 4: 2014133 XT-PIC serial
+ 5: 44401 XT-PIC pcnet_cs
+ 8: 2 XT-PIC rtc
+ 11: 8 XT-PIC i82365
+ 12: 182918 XT-PIC PS/2 Mouse
+ 13: 1 XT-PIC fpu
+ 14: 1232265 XT-PIC ide0
+ 15: 7 XT-PIC ide1
+ NMI: 0
+
+
+There are three more important subdirectories in /proc: net, scsi, and sys.
+The general rule is that the contents, or even the existence of these
+directories, depend on your kernel configuration. If SCSI is not enabled, the
+directory scsi may not exist. The same is true with the net, which is there
+only when networking support is present in the running kernel.
+
+The slabinfo file gives information about memory usage at the slab level.
+Linux uses slab pools for memory management above page level in version 2.2.
+Commonly used objects have their own slab pool (such as network buffers,
+directory cache, and so on).
+
+1.3 IDE devices in /proc/ide
+----------------------------
+
+The subdirectory /proc/ide contains information about all IDE devices of which
+the kernel is aware. There is one subdirectory for each IDE controller, the
+file drivers and a link for each IDE device, pointing to the device directory
+in the controller specific subtree.
+
+The file drivers contains general information about the drivers used for the
+IDE devices:
+
+ > cat /proc/ide/drivers
+ ide-cdrom version 4.53
+ ide-disk version 1.08
+
+
+More detailed information can be found in the controller specific
+subdirectories. These are named ide0, ide1 and so on. Each of these
+directories contains the files shown in table 1-4.
+
+
+Table 1-4: IDE controller info in /proc/ide/ide?
+..............................................................................
+ File Content
+ channel IDE channel (0 or 1)
+ config Configuration (only for PCI/IDE bridge)
+ mate Mate name
+ model Type/Chipset of IDE controller
+..............................................................................
+
+Each device connected to a controller has a separate subdirectory in the
+controllers directory. The files listed in table 1-5 are contained in these
+directories.
+
+
+Table 1-5: IDE device information
+..............................................................................
+ File Content
+ cache The cache
+ capacity Capacity of the medium (in 512Byte blocks)
+ driver driver and version
+ geometry physical and logical geometry
+ identify device identify block
+ media media type
+ model device identifier
+ settings device setup
+ smart_thresholds IDE disk management thresholds
+ smart_values IDE disk management values
+..............................................................................
+
+The most interesting file is settings. This file contains a nice overview of
+the drive parameters:
+
+ # cat /proc/ide/ide0/hda/settings
+ name value min max mode
+ ---- ----- --- --- ----
+ bios_cyl 526 0 65535 rw
+ bios_head 255 0 255 rw
+ bios_sect 63 0 63 rw
+ breada_readahead 4 0 127 rw
+ bswap 0 0 1 r
+ file_readahead 72 0 2097151 rw
+ io_32bit 0 0 3 rw
+ keepsettings 0 0 1 rw
+ max_kb_per_request 122 1 127 rw
+ multcount 0 0 8 rw
+ nice1 1 0 1 rw
+ nowerr 0 0 1 rw
+ pio_mode write-only 0 255 w
+ slow 0 0 1 rw
+ unmaskirq 0 0 1 rw
+ using_dma 0 0 1 rw
+
+
+1.4 Networking info in /proc/net
+--------------------------------
+
+The subdirectory /proc/net follows the usual pattern. Table 1-6 shows the
+additional values you get for IP version 6 if you configure the kernel to
+support this. Table 1-7 lists the files and their meaning.
+
+
+Table 1-6: IPv6 info in /proc/net
+..............................................................................
+ File Content
+ udp6 UDP sockets (IPv6)
+ tcp6 TCP sockets (IPv6)
+ raw6 Raw device statistics (IPv6)
+ igmp6 IP multicast addresses, which this host joined (IPv6)
+ if_inet6 List of IPv6 interface addresses
+ ipv6_route Kernel routing table for IPv6
+ rt6_stats Global IPv6 routing tables statistics
+ sockstat6 Socket statistics (IPv6)
+ snmp6 Snmp data (IPv6)
+..............................................................................
+
+
+Table 1-7: Network info in /proc/net
+..............................................................................
+ File Content
+ arp Kernel ARP table
+ dev network devices with statistics
+ dev_mcast the Layer2 multicast groups a device is listening too
+ (interface index, label, number of references, number of bound
+ addresses).
+ dev_stat network device status
+ ip_fwchains Firewall chain linkage
+ ip_fwnames Firewall chain names
+ ip_masq Directory containing the masquerading tables
+ ip_masquerade Major masquerading table
+ netstat Network statistics
+ raw raw device statistics
+ route Kernel routing table
+ rpc Directory containing rpc info
+ rt_cache Routing cache
+ snmp SNMP data
+ sockstat Socket statistics
+ tcp TCP sockets
+ tr_rif Token ring RIF routing table
+ udp UDP sockets
+ unix UNIX domain sockets
+ wireless Wireless interface data (Wavelan etc)
+ igmp IP multicast addresses, which this host joined
+ psched Global packet scheduler parameters.
+ netlink List of PF_NETLINK sockets
+ ip_mr_vifs List of multicast virtual interfaces
+ ip_mr_cache List of multicast routing cache
+..............................................................................
+
+You can use this information to see which network devices are available in
+your system and how much traffic was routed over those devices:
+
+ > cat /proc/net/dev
+ Inter-|Receive |[...
+ face |bytes packets errs drop fifo frame compressed multicast|[...
+ lo: 908188 5596 0 0 0 0 0 0 [...
+ ppp0:15475140 20721 410 0 0 410 0 0 [...
+ eth0: 614530 7085 0 0 0 0 0 1 [...
+
+ ...] Transmit
+ ...] bytes packets errs drop fifo colls carrier compressed
+ ...] 908188 5596 0 0 0 0 0 0
+ ...] 1375103 17405 0 0 0 0 0 0
+ ...] 1703981 5535 0 0 0 3 0 0
+
+
+1.5 SCSI info
+-------------
+
+If you have a SCSI host adapter in your system, you'll find a subdirectory
+named after the driver for this adapter in /proc/scsi. You'll also see a list
+of all recognized SCSI devices in /proc/scsi:
+
+ >cat /proc/scsi/scsi
+ Attached devices:
+ Host: scsi0 Channel: 00 Id: 00 Lun: 00
+ Vendor: IBM Model: DGHS09U Rev: 03E0
+ Type: Direct-Access ANSI SCSI revision: 03
+ Host: scsi0 Channel: 00 Id: 06 Lun: 00
+ Vendor: PIONEER Model: CD-ROM DR-U06S Rev: 1.04
+ Type: CD-ROM ANSI SCSI revision: 02
+
+
+The directory named after the driver has one file for each adapter found in
+the system. These files contain information about the controller, including
+the used IRQ and the IO address range. The amount of information shown is
+dependent on the adapter you use. The example shows the output for an Adaptec
+AHA-2940 SCSI adapter:
+
+ > cat /proc/scsi/aic7xxx/0
+
+ Adaptec AIC7xxx driver version: 5.1.19/3.2.4
+ Compile Options:
+ TCQ Enabled By Default : Disabled
+ AIC7XXX_PROC_STATS : Disabled
+ AIC7XXX_RESET_DELAY : 5
+ Adapter Configuration:
+ SCSI Adapter: Adaptec AHA-294X Ultra SCSI host adapter
+ Ultra Wide Controller
+ PCI MMAPed I/O Base: 0xeb001000
+ Adapter SEEPROM Config: SEEPROM found and used.
+ Adaptec SCSI BIOS: Enabled
+ IRQ: 10
+ SCBs: Active 0, Max Active 2,
+ Allocated 15, HW 16, Page 255
+ Interrupts: 160328
+ BIOS Control Word: 0x18b6
+ Adapter Control Word: 0x005b
+ Extended Translation: Enabled
+ Disconnect Enable Flags: 0xffff
+ Ultra Enable Flags: 0x0001
+ Tag Queue Enable Flags: 0x0000
+ Ordered Queue Tag Flags: 0x0000
+ Default Tag Queue Depth: 8
+ Tagged Queue By Device array for aic7xxx host instance 0:
+ {255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255}
+ Actual queue depth per device for aic7xxx host instance 0:
+ {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1}
+ Statistics:
+ (scsi0:0:0:0)
+ Device using Wide/Sync transfers at 40.0 MByte/sec, offset 8
+ Transinfo settings: current(12/8/1/0), goal(12/8/1/0), user(12/15/1/0)
+ Total transfers 160151 (74577 reads and 85574 writes)
+ (scsi0:0:6:0)
+ Device using Narrow/Sync transfers at 5.0 MByte/sec, offset 15
+ Transinfo settings: current(50/15/0/0), goal(50/15/0/0), user(50/15/0/0)
+ Total transfers 0 (0 reads and 0 writes)
+
+
+1.6 Parallel port info in /proc/parport
+---------------------------------------
+
+The directory /proc/parport contains information about the parallel ports of
+your system. It has one subdirectory for each port, named after the port
+number (0,1,2,...).
+
+These directories contain the four files shown in Table 1-8.
+
+
+Table 1-8: Files in /proc/parport
+..............................................................................
+ File Content
+ autoprobe Any IEEE-1284 device ID information that has been acquired.
+ devices list of the device drivers using that port. A + will appear by the
+ name of the device currently using the port (it might not appear
+ against any).
+ hardware Parallel port's base address, IRQ line and DMA channel.
+ irq IRQ that parport is using for that port. This is in a separate
+ file to allow you to alter it by writing a new value in (IRQ
+ number or none).
+..............................................................................
+
+1.7 TTY info in /proc/tty
+-------------------------
+
+Information about the available and actually used tty's can be found in the
+directory /proc/tty.You'll find entries for drivers and line disciplines in
+this directory, as shown in Table 1-9.
+
+
+Table 1-9: Files in /proc/tty
+..............................................................................
+ File Content
+ drivers list of drivers and their usage
+ ldiscs registered line disciplines
+ driver/serial usage statistic and status of single tty lines
+..............................................................................
+
+To see which tty's are currently in use, you can simply look into the file
+/proc/tty/drivers:
+
+ > cat /proc/tty/drivers
+ pty_slave /dev/pts 136 0-255 pty:slave
+ pty_master /dev/ptm 128 0-255 pty:master
+ pty_slave /dev/ttyp 3 0-255 pty:slave
+ pty_master /dev/pty 2 0-255 pty:master
+ serial /dev/cua 5 64-67 serial:callout
+ serial /dev/ttyS 4 64-67 serial
+ /dev/tty0 /dev/tty0 4 0 system:vtmaster
+ /dev/ptmx /dev/ptmx 5 2 system
+ /dev/console /dev/console 5 1 system:console
+ /dev/tty /dev/tty 5 0 system:/dev/tty
+ unknown /dev/tty 4 1-63 console
+
+
+------------------------------------------------------------------------------
+Summary
+------------------------------------------------------------------------------
+The /proc file system serves information about the running system. It not only
+allows access to process data but also allows you to request the kernel status
+by reading files in the hierarchy.
+
+The directory structure of /proc reflects the types of information and makes
+it easy, if not obvious, where to look for specific data.
+------------------------------------------------------------------------------
+
+------------------------------------------------------------------------------
+CHAPTER 2: MODIFYING SYSTEM PARAMETERS
+------------------------------------------------------------------------------
+
+------------------------------------------------------------------------------
+In This Chapter
+------------------------------------------------------------------------------
+* Modifying kernel parameters by writing into files found in /proc/sys
+* Exploring the files which modify certain parameters
+* Review of the /proc/sys file tree
+------------------------------------------------------------------------------
+
+
+A very interesting part of /proc is the directory /proc/sys. This is not only
+a source of information, it also allows you to change parameters within the
+kernel. Be very careful when attempting this. You can optimize your system,
+but you can also cause it to crash. Never alter kernel parameters on a
+production system. Set up a development machine and test to make sure that
+everything works the way you want it to. You may have no alternative but to
+reboot the machine once an error has been made.
+
+To change a value, simply echo the new value into the file. An example is
+given below in the section on the file system data. You need to be root to do
+this. You can create your own boot script to perform this every time your
+system boots.
+
+The files in /proc/sys can be used to fine tune and monitor miscellaneous and
+general things in the operation of the Linux kernel. Since some of the files
+can inadvertently disrupt your system, it is advisable to read both
+documentation and source before actually making adjustments. In any case, be
+very careful when writing to any of these files. The entries in /proc may
+change slightly between the 2.1.* and the 2.2 kernel, so if there is any doubt
+review the kernel documentation in the directory /usr/src/linux/Documentation.
+This chapter is heavily based on the documentation included in the pre 2.2
+kernels, and became part of it in version 2.2.1 of the Linux kernel.
------------------------------------------------------------------------
+2.1 /proc/sys/fs - File system data
+-----------------------------------
- T H E /proc F I L E S Y S T E M
-
------------------------------------------------------------------------
-/proc/sys Terrehon Bowden <terrehon@wpi.com> January 27 1999
- Bodo Bauer <bb@ricochet.net>
------------------------------------------------------------------------
-Version 1.1 Kernel version 2.2
------------------------------------------------------------------------
-Contents
-
-1 Introduction/Credits
-
-1.1 Legal Issues
-
-2 The /proc file system
-
-2.1 Process specific subdirectories
-2.2 Kernel data
-2.3 IDE devices in /proc/ide
-2.4 Networking info in /proc/net
-2.5 SCSI info
-2.6 Parallel port info in /proc/parport
-2.7 TTY info in /proc/tty
-
-3 Reading and modifying kernel parameters
-
-3.1 /proc/sys/debug and /proc/sys/proc
-3.2 /proc/fs - File system data
-3.3 /proc/fs/binfmt_misc - Miscellaneous binary formats
-3.4 /proc/sys/kernel - General kernel parameters
-3.5 /proc/sys/vm - The virtual memory subsystem
-3.6 /proc/sys/dev - Device specific parameters
-3.7 /proc/sys/sunrpc - Remote procedure calls
-3.8 /proc/sys/net - Networking stuff
-3.9 /proc/sys/net/ipv4 - IPV4 settings=20
-3.10 Appletalk
-3.11 IPX
-
------------------------------------------------------------------------
-
-1 Introduction/Credits
-
-This documentation is part of a soon to be released book published by
-IDG Books on the SuSE Linux distribution. As there is no complete
-documentation for the /proc file system and we've used many freely
-available sources to write this chapter, it seems only fair to give
-the work back to the Linux community. This work is based on the
-2.1.132 and 2.2.0-pre-kernel versions. I'm afraid it's still far from
-complete, but we hope it will be useful. As far as we know, it is the
-first 'all-in-one' document about the /proc file system. It is
-focused on the Intel x86 hardware, so if you are looking for PPC, ARM,
-SPARC, APX, etc., features, you probably won't find what you are
-looking for. It also only covers IPv4 networking, not IPv6 nor other
-protocols - sorry.
-
-We'd like to thank Alan Cox, Rik van Riel, and Alexey Kuznetsov. We'd
-also like to extend a special thank you to Andi Kleen for
-documentation, which we relied on heavily to create this document, as
-well as the additional information he provided. Thanks to everybody
-else who contributed source or docs to the Linux kernel and helped
-create a great piece of software... :)
-
-If you have any comments, corrections or additions, please don't
-hesitate to contact Bodo Bauer at bb@ricochet.net. We'll be happy to
-add them to this document.
-
-The latest version of this document is available online at
-http://www.suse.com/~bb/Docs/proc.html in HTML, ASCII, and as
-Postscript file.
-
-1.1 Legal Stuff
-
-We don't guarantee the correctness of this document, and if you come
-to us complaining about how you screwed up your system because of
-incorrect documentation, we won't feel responsible...
-
------------------------------------------------------------------------
-
-2 The /proc file system
-
-The proc file system acts as an interface to internal data structures
-in the kernel. It can be used to obtain information about the system
-and to change certain kernel parameters at runtime. It contains
-(among other things) one subdirectory for each process running on the
-system which is named after the process id (PID) of the process. The
-link self points to the process reading the file system.
-
-2.1 Process specific subdirectories
-
-Each process subdirectory has the in table 1.1 listed entries.
-
- _________________________________________________
- cmdline Command line arguments
- environ Values of environment variables
- fd Directory, which contains all file descriptors
- mem Memory held by this process
- stat Process status
- status Process status in human readable form
- cwd Link to the current working directory
- exe Link to the executable of this process
- maps Memory maps
- root Link to the root directory of this process
- statm Process memory status information
- _________________________________________________
- Table 1.1: Process specific entries in /proc
-
-For example, to get the status information of a process, all you have
-to do is read the file /proc/PID/status:
-
-> cat /proc/self/status
-Name: cat
-State: R (running)
-Pid: 5633
-PPid: 5609
-Uid: 501 501 501 501
-Gid: 100 100 100 100
-Groups: 100 16
-VmSize: 804 kB
-VmLck: 0 kB
-VmRSS: 344 kB
-VmData: 68 kB
-VmStk: 20 kB
-VmExe: 12 kB
-VmLib: 660 kB
-SigPnd: 0000000000000000
-SigBlk: 0000000000000000
-SigIgn: 0000000000000000
-SigCgt: 0000000000000000
-CapInh: 00000000fffffeff
-CapPrm: 0000000000000000
-CapEff: 0000000000000000
-
-This shows you almost the same information as you would get if you
-viewed it with the ps command. In fact, ps uses the proc file system
-to obtain its information.
-
-The statm file contains more detailed information about the process
-memory usage. It contains seven values with the following meanings:
-
-size total program size
-resident size of in memory portions
-shared number of the pages that are shared
-trs number of pages that are 'code'
-drs number of pages of data/stack
-lrs number of pages of library
-dt number of dirty pages
-
-The ratio text/data/library is approximate only by heuristics.
-
-2.2 Kernel data
-
-Similar to the process entries, these are files which give information
-about the running kernel. The files used to obtain this information
-are contained in /proc and are listed in table 1.2. Not all of these
-will be present in your system. It depends on the kernel configuration
-and the loaded modules, which files are there, and which are missing.
-
- ________________________________________________
- apm Advanced power management info
- cmdline Kernel command line
- cpuinfo Info about the CPU
- devices Available devices (block and character)
- dma Used DMS channels
- filesystems Supported filesystems
- interrupts Interrupt usage
- ioports I/O port usage
- kcore Kernel core image
- kmsg Kernel messages
- ksyms Kernel symbol table
- loadavg Load average
- locks Kernel locks
- meminfo Memory info
- misc Miscellaneous
- modules List of loaded modules
- mounts Mounted filesystems
- partitions Table of partitions known to the system
- rtc Real time clock
- slabinfo Slab pool info
- stat Overall statistics
- swaps Swap space utilization
- uptime System uptime
- version Kernel version
- ________________________________________________
- Table 1.2: Kernel info in /proc
-
-You can, for example, check which interrupts are currently in use and
-what they are used for by looking in the file /proc/interrupts:
-
-> cat /proc/interrupts
- CPU0
- 0: 8728810 XT-PIC timer
- 1: 895 XT-PIC keyboard
- 2: 0 XT-PIC cascade
- 3: 531695 XT-PIC aha152x
- 4: 2014133 XT-PIC serial
- 5: 44401 XT-PIC pcnet_cs
- 8: 2 XT-PIC rtc
- 11: 8 XT-PIC i82365
- 12: 182918 XT-PIC PS/2 Mouse
- 13: 1 XT-PIC fpu
- 14: 1232265 XT-PIC ide0
- 15: 7 XT-PIC ide1
-NMI: 0
-
-There three more important subdirectories in /proc: net, scsi and
-sys. The general rule is that the contents, or even the existence of
-these directories, depends on your kernel configuration. If SCSI is
-not enabled, the directory scsi may not exist. The same is true with
-the net, which is only there when networking support is present in the
-running kernel.
-
-The slabinfo file gives information about memory usage on the slab
-level. Linux uses slab pools for memory management above page level
-in version 2.2. Commonly used objects have their own slab pool (like
-network buffers, directory cache, etc.).
-
-2.3 IDE devices in /proc/ide
-
-This subdirectory contains information about all IDE devices that the
-kernel is aware of. There is one subdirectory for each device
-(i.e. hard disk) containing the following files:
-
- cache The cache
- capacity Capacity of the medium
- driver Driver and version
- geometry Physical and logical geometry
- identify Device identify block
- media Media type
- model Device identifier
- settings Device setup
- smart_thresholds IDE disk management thresholds
- smart_values IDE disk management values
-
-2.4 Networking info in /proc/net
-
-This directory follows the usual pattern. Table 1.3 lists the files
-and their meaning.
-
- ____________________________________________________
- arp Kernel ARP table
- dev network devices with statistics
- dev_mcast Lists the Layer2 multicast groups a
- device is listening to (interface index,
- label, number of references, number of
- bound addresses).
- dev_stat network device status
- ip_fwchains Firewall chain linkage
- ip_fwnames Firewall chains
- ip_masq Directory containing the masquerading
- tables.
- ip_masquerade Major masquerading table
- netstat Network statistics
- raw Raw device statistics
- route Kernel routing table
- rpc Directory containing rpc info
- rt_cache Routing cache
- snmp SNMP data
- sockstat Socket statistics
- tcp TCP sockets
- tr_rif Token ring RIF routing table
- udp UDP sockets
- unix UNIX domain sockets
- wireless Wireless interface data (Wavelan etc)
- igmp IP multicast addresses, which this host joined
- psched Global packet scheduler parameters.
- netlink List of PF_NETLINK sockets.
- ip_mr_vifs List of multicast virtual interfaces.
- ip_mr_cache List of multicast routing cache.
- udp6 UDP sockets (IPv6)
- tcp6 TCP sockets (IPv6)
- raw6 Raw device statistics (IPv6)
- igmp6 IP multicast addresses, which this host joineed (IPv6)
- if_inet6 List of IPv6 interface addresses.
- ipv6_route Kernel routing table for IPv6
- rt6_stats global IPv6 routing tables statistics.
- sockstat6 Socket statistics (IPv6)
- snmp6 Snmp data (IPv6)
- ____________________________________________________
- Table 1.3: Network info in /proc/net
-
-You can use this information to see which network devices are
-available in your system and how much traffic was routed over those
-devices:
-
-> cat /proc/net/dev
-Inter-|Receive |[...
- face |bytes packets errs drop fifo frame compressed multicast|[...
- lo: 908188 5596 0 0 0 0 0 0 [...
- ppp0:15475140 20721 410 0 0 410 0 0 [...
- eth0: 614530 7085 0 0 0 0 0 1 [...
-
-...] Transmit
-...] bytes packets errs drop fifo colls carrier compressed
-...] 908188 5596 0 0 0 0 0 0
-...] 1375103 17405 0 0 0 0 0 0
-...] 1703981 5535 0 0 0 3 0 0
-
-2.5 SCSI info
-
-If you have a SCSI host adapter in your system, you'll find a
-subdirectory named after the driver for this adapter in /proc/scsi.
-You'll also see a list of all recognized SCSI devices in /proc/scsi:
-
->cat /proc/scsi/scsi
-Attached devices:
-Host: scsi0 Channel: 00 Id: 00 Lun: 00
- Vendor: QUANTUM Model: XP34550W Rev: LXY4
- Type: Direct-Access ANSI SCSI revision: 02
-Host: scsi0 Channel: 00 Id: 01 Lun: 00
- Vendor: SEAGATE Model: ST34501W Rev: 0018
- Type: Direct-Access ANSI SCSI revision: 02
-Host: scsi0 Channel: 00 Id: 02 Lun: 00
- Vendor: SEAGATE Model: ST34501W Rev: 0017
- Type: Direct-Access ANSI SCSI revision: 02
-Host: scsi0 Channel: 00 Id: 04 Lun: 00
- Vendor: ARCHIVE Model: Python 04106-XXX Rev: 703b
- Type: Sequential-Access ANSI SCSI revision: 02
-
-The directory named after the driver has one file for each adapter
-found in the system. These files contain information about
-the controller, including the used IRQ and the IO address range:
-
->cat /proc/scsi/ncr53c8xx/0
-General information:
- Chip NCR53C875, device id 0xf, revision id 0x4
- IO port address 0xec00, IRQ number 11
- Synchronous period factor 12, max commands per lun 4
-
-2.6 Parallel port info in /proc/parport
-
-The directory /proc/parport contains information about the parallel
-ports of your system. It has one subdirectory for each port, named
-after the port number (0,1,2,...).
-
-This directory contains four files:
-
- autoprobe Autoprobe results of this port
- devices Connected device modules
- hardware Hardware info (port type, io-port, DMA, IRQ, etc.)
- irq Used interrupt, if any
-
-2.7 TTY info in /proc/tty
-
-Information about the available and the actually used tty's can be
-found in /proc/tty. You'll find entries for drivers and line
-disciplines in this directory, as shown in the table below:
-
- drivers List of drivers and their usage
- ldiscs Registered line disciplines
- driver/serial Usage statistic and status of single tty lines
-
-To see which tty's are currently in use, you can simply look into the
-file /proc/tty/drivers:
-
->cat /proc/tty/drivers
-pty_slave /dev/pts 136 0-255 pty:slave
-pty_master /dev/ptm 128 0-255 pty:master
-pty_slave /dev/ttyp 3 0-255 pty:slave
-pty_master /dev/pty 2 0-255 pty:master
-serial /dev/cua 5 64-67 serial:callout
-serial /dev/ttyS 4 64-67 serial
-/dev/tty0 /dev/tty0 4 0 system:vtmaster
-/dev/ptmx /dev/ptmx 5 2 system
-/dev/console /dev/console 5 1 system:console
-/dev/tty /dev/tty 5 0 system:/dev/tty
-unknown /dev/tty 4 1-63 console
-
------------------------------------------------------------------------
-
-3 Reading and modifying kernel parameters
-
-A very interesting part of /proc is the directory /proc/sys. This not
-only provides information, it also allows you to change parameters
-within the kernel. Be very careful when trying this. You can optimize
-your system, but you also can crash it. Never play around with kernel
-parameters on a production system. Set up a development machine and
-test to make sure that everything works the way you want it to. You
-may have no alternative but to reboot the machine once an error has
-been made.
-
-To change a value, simply echo the new value into the file. An example
-is given below in the section on the file system data. You need to be
-root to do this. You can create your own boot script to get this done
-every time your system boots.
-
-The files in /proc/sys can be used to tune and monitor miscellaneous
-and general things in the operation of the Linux kernel. Since some
-of the files can inadvertently disrupt your system, it is advisable to
-read both documentation and source before actually making
-adjustments. In any case, be very careful when writing to any of these
-files. The entries in /proc may change slightly between the 2.1.* and
-the 2.2 kernel, so review the kernel documentation if there is any
-doubt. You'll find the documentation in the directory
-/usr/src/linux/Documentation/sys. This chapter is heavily based on the
-documentation included in the pre 2.2 kernels. Thanks to Rick van Riel
-for providing this information.
-
-3.1 /proc/sys/debug and /proc/sys/proc
-
-These two subdirectories are empty.
-
-3.2 /proc/fs - File system data
-
-This subdirectory contains specific file system, file handle, inode,
-dentry and quota information.
+This subdirectory contains specific file system, file handle, inode, dentry
+and quota information.
Currently, these files are in /proc/sys/fs:
dentry-state
- Status of the directory cache. Since directory entries are
- dynamically allocated and deallocated, this file gives information
- about the current status. It holds six values, in which the last
- two are not used and are always zero. The other four mean:
-
- nr_dentry Seems to be zero all the time
- nr_unused Number of unused cache entries
- age_limit Age in seconds after the entry may be
- reclaimed, when memory is short
- want_pages internal
+------------
+
+Status of the directory cache. Since directory entries are dynamically
+allocated and deallocated, this file indicates the current status. It holds
+six values, in which the last two are not used and are always zero. The others
+are listed in table 2-1.
+
+
+Table 2-1: Status files of the directory cache
+..............................................................................
+ File Content
+ nr_dentry Almost always zero
+ nr_unused Number of unused cache entries
+ age_limit
+ in seconds after the entry may be reclaimed, when memory is short
+ want_pages internally
+..............................................................................
dquot-nr and dquot-max
- The file dquot-max shows the maximum number of cached disk quota
- entries.
+----------------------
+
+The file dquot-max shows the maximum number of cached disk quota entries.
- The file dquot-nr shows the number of allocated disk quota
- entries and the number of free disk quota entries.
+The file dquot-nr shows the number of allocated disk quota entries and the
+number of free disk quota entries.
- If the number of free cached disk quotas is very low and you have
- a large number of simultaneous system users, you might want
- to raise the limit.
+If the number of available cached disk quotas is very low and you have a large
+number of simultaneous system users, you might want to raise the limit.
file-nr and file-max
- The kernel allocates file handles dynamically, but as yet
- doesn't free them again.
+--------------------
- The value in file-max denotes the maximum number of file handles
- that the Linux kernel will allocate. When you get a lot of error
- messages about running out of file handles, you might want to raise
- this limit. The default value is 4096. To change it, just write the
- new number into the file:
-
- # cat /proc/sys/fs/file-max
- 4096
- # echo 8192 > /proc/sys/fs/file-max
- # cat /proc/sys/fs/file-max
- 8192
-
- This method of revision is useful for all customizable parameters
- of the kernel - simply echo the new value to the corresponding
- file.
-
- The three values in file-nr denote the number of allocated file
- handles, the number of used file handles, and the maximum number of
- file handles. When the allocated file handles come close to the
- maximum, but the number of actually used ones is far behind, you've
- encountered a peak in your usage of file handles and you don't need
- to increase the maximum.
-
- However, there is still a per process limit of open files, which
- unfortunatly can't be changed that easily. It is set to 1024 by
- default. To change this you have to edit the files limits.h and
- fs.h in the directory /usr/src/linux/include/linux. Change the
- definition of NR_OPEN and recompile the kernel.
+The kernel allocates file handles dynamically, but doesn't free them again at
+this time.
+
+The value in file-max denotes the maximum number of file handles that the
+Linux kernel will allocate. When you get a lot of error messages about running
+out of file handles, you might want to raise this limit. The default value is
+4096. To change it, just write the new number into the file:
+
+ # cat /proc/sys/fs/file-max
+ 4096
+ # echo 8192 > /proc/sys/fs/file-max
+ # cat /proc/sys/fs/file-max
+ 8192
+
+
+This method of revision is useful for all customizable parameters of the
+kernel - simply echo the new value to the corresponding file.
+
+The three values in file-nr denote the number of allocated file handles, the
+number of used file handles, and the maximum number of file handles. When the
+allocated file handles come close to the maximum, but the number of actually
+used ones is far behind, you've encountered a peak in your usage of file
+handles and you don't need to increase the maximum.
+
+However, there is still a per process limit of open files, which unfortunately
+can't be changed that easily. It is set to 1024 by default. To change this you
+have to edit the files limits.h and fs.h in the kernel source tree. Finally,
+change the definition of NR_OPEN and recompile the kernel.
inode-state, inode-nr and inode-max
- As with file handles, the kernel allocates the inode structures
- dynamically, but can't free them yet.
+-----------------------------------
+
+As with file handles, the kernel allocates the inode structures dynamically,
+but can't free them yet.
+
+The value in inode-max denotes the maximum number of inode handlers. This
+value should be 3 to 4 times larger than the value in file-max, since stdin,
+stdout, and network sockets also need an inode struct to handle them. If you
+regularly run out of inodes, you should increase this value.
+
+The file inode-nr contains the first two items from inode-state, so we'll skip
+to that file...
+
+inode-state contains three actual numbers and four dummy values. The numbers
+are nr_inodes, nr_free_inodes, and preshrink (in order of appearance).
+
+nr_inodes
+~~~~~~~~~
+
+Denotes the number of inodes the system has allocated. This can be slightly
+more than inode-max because Linux allocates them one pageful at a time.
+
+nr_free_inodes
+--------------
+
+Represents the number of free inodes and preshrink is nonzero when nr_inodes
+is greater than inode-max and the system needs to prune the inode list instead
+of allocating more.
- The value in inode-max denotes the maximum number of inode
- handlers. This value should be 3 to 4 times larger than the value
- in file-max, since stdin, stdout, and network sockets also need an
- inode struct to handle them. If you regularly run out of inodes,
- you should increase this value.
-
- The file inode-nr contains the first two items from inode-state, so
- we'll skip to that file...
-
- inode-state contains three actual numbers and four dummy values. The
- actual numbers are (in order of appearance) nr_inodes, nr_free_inodes,
- and preshrink.
-
- nr_inodes
- Denotes the number of inodes the system has allocated. This can
- be slightly more than inode-max because Linux allocates them one
- pageful at a time.
-
- nr_free_inodes
- Represents the number of free inodes and pre shrink is nonzero
- when the nr_inodes > inode-max and the system needs to prune the
- inode list instead of allocating more.
super-nr and super-max
- Again, super block structures are allocated by the kernel,
- but not freed. The file super-max contains the maximum number of
- super block handlers, where super-nr shows the number of
- currently allocated ones.
-
- Every mounted file system needs a super block, so if you plan to
- mount lots of file systems, you may want to increase these
- numbers.
-
-3.3 /proc/fs/binfmt_misc - Miscellaneous binary formats
-
-Besides these files, there is the subdirectory
-/proc/sys/fs/binfmt_misc. This handles the kernel support for
-miscellaneous binary formats.
-
-Binfmt_misc provides the ability to register additional binary formats
-to the Kernel without compiling an additional module/kernel. Therefore
-binfmt_misc needs to know magic numbers at the beginning or the
-filename extension of the binary.
-
-It works by maintaining a linked list of structs, that contain a
-description of a binary format, including a magic with size (or the
-filename extension), offset and mask, and the interpreter name. On
-request it invokes the given interpreter with the original program as
-argument, as binfmt_java and binfmt_em86 and binfmt_mz do.
-Since binfmt_misc does not define any default binary-formats, you have to
-register an additional binary-format.
+----------------------
+
+Again, super block structures are allocated by the kernel, but not freed. The
+file super-max contains the maximum number of super block handlers, where
+super-nr shows the number of currently allocated ones.
+
+Every mounted file system needs a super block, so if you plan to mount lots of
+file systems, you may want to increase these numbers.
+
+2.2 /proc/sys/fs/binfmt_misc - Miscellaneous binary formats
+-----------------------------------------------------------
+
+Besides these files, there is the subdirectory /proc/sys/fs/binfmt_misc. This
+handles the kernel support for miscellaneous binary formats.
+
+Binfmt_misc provides the ability to register additional binary formats to the
+Kernel without compiling an additional module/kernel. Therefore, binfmt_misc
+needs to know magic numbers at the beginning or the filename extension of the
+binary.
+
+It works by maintaining a linked list of structs that contain a description of
+a binary format, including a magic with size (or the filename extension),
+offset and mask, and the interpreter name. On request it invokes the given
+interpreter with the original program as argument, as binfmt_java and
+binfmt_em86 and binfmt_mz do. Since binfmt_misc does not define any default
+binary-formats, you have to register an additional binary-format.
-There are two general files in binfmt_misc and one file per registered
-format. The two general files are register and status.
+There are two general files in binfmt_misc and one file per registered format.
+The two general files are register and status.
Registering a new binary format
+-------------------------------
-echo :name:type:offset:magic:mask:interpreter: > /proc/sys/fs/binfmt_misc/register
+To register a new binary format you have to issue the command
-with appropriate name (the name for the /proc-dir entry), offset
-(defaults to 0, if omitted), magic and mask (which can be omitted,
-defaults to all 0xff) and last but not least, the interpreter that is
-to be invoked (for example and testing '/bin/echo'). Type can be M for
-usual magic matching or E for filename extension matching (give
-extension in place of magic).
-
-To check or reset the status of the binary format handler:
-
-If you do a cat on the file /proc/sys/fs/binfmt_misc/status, you will
-get the current status (enabled/disabled) of binfmt_misc. Change the
-status by echoing 0 (disables) or 1 (enables) or -1 (caution: this
-clears all previously registered binary formats) to status. For
-example echo 0 > status to disable binfmt_misc (temporarily).
+ echo :name:type:offset:magic:mask:interpreter: > /proc/sys/fs/binfmt_misc/register
+
+
+
+with appropriate name (the name for the /proc-dir entry), offset (defaults to
+0, if omitted), magic, mask (which can be omitted, defaults to all 0xff) and
+last but not least, the interpreter that is to be invoked (for example and
+testing /bin/echo). Type can be M for usual magic matching or E for filename
+extension matching (give extension in place of magic).
+
+Check or reset the status of the binary format handler
+------------------------------------------------------
+
+If you do a cat on the file /proc/sys/fs/binfmt_misc/status, you will get the
+current status (enabled/disabled) of binfmt_misc. Change the status by echoing
+0 (disables) or 1 (enables) or -1 (caution: this clears all previously
+registered binary formats) to status. For example echo 0 > status to disable
+binfmt_misc (temporarily).
Status of a single handler
+--------------------------
-Each registered handler has an entry in /proc/sys/fs/binfmt_misc.
-These files perform the same function as status, but their scope is
-limited to the actual binary format. By cating this file, you also
-receive all related information about the interpreter/magic of the
-binfmt.
+Each registered handler has an entry in /proc/sys/fs/binfmt_misc. These files
+perform the same function as status, but their scope is limited to the actual
+binary format. By cating this file, you also receive all related information
+about the interpreter/magic of the binfmt.
Example usage of binfmt_misc (emulate binfmt_java)
+--------------------------------------------------
-cd /proc/sys/fs/binfmt_misc
-echo ':Java:M::\xca\xfe\xba\xbe::/usr/local/java/bin/javawrapper:' > register
-echo ':HTML:E::html::/usr/local/java/bin/appletviewer:' > register
-echo ':Applet:M::<!--applet::/usr/local/java/bin/appletviewer:' > register
-echo ':DEXE:M::\x0eDEX::/usr/bin/dosexec:' > register
-
-These three lines add support for Java executables and Java applets
-(like binfmt_java, additionally recognizing the .html extension with
-no need to put <!--applet> to every applet file). You have to install
-the JDK and the shell-script /usr/local/java/bin/javawrapper too. It
-works around the brokenness of the Java filename handling. To add a
-Java binary, just create a link to the class-file somewhere in the
-path.
-
-3.4 /proc/sys/kernel - general kernel parameters
-
-This directory reflects general kernel behaviors. As I've said before,
-the contents are depend on your configuration. I'll list the most
-important files, along with descriptions of what they mean and how to
-use them.
+ cd /proc/sys/fs/binfmt_misc
+ echo ':Java:M::\xca\xfe\xba\xbe::/usr/local/java/bin/javawrapper:' > register
+ echo ':HTML:E::html::/usr/local/java/bin/appletviewer:' > register
+ echo ':Applet:M::<!--applet::/usr/local/java/bin/appletviewer:' > register
+ echo ':DEXE:M::\x0eDEX::/usr/bin/dosexec:' > register
+
+
+These four lines add support for Java executables and Java applets (like
+binfmt_java, additionally recognizing the .html extension with no need to put
+<!--applet> to every applet file). You have to install the JDK and the
+shell-script /usr/local/java/bin/javawrapper too. It works around the
+brokenness of the Java filename handling. To add a Java binary, just create a
+link to the class-file somewhere in the path.
+
+2.3 /proc/sys/kernel - general kernel parameters
+------------------------------------------------
+
+This directory reflects general kernel behaviors. As I've said before, the
+contents depend on your configuration. Here you'll find the most important
+files, along with descriptions of what they mean and how to use them.
acct
- The file contains three values; highwater, lowwater, and
- frequency.
+----
- It exists only when BSD-style process accounting is enabled. These
- values control its behavior. If the free space on the file system
- where the log lives goes below lowwater%, accounting suspends. If
- it goes above highwater%, accounting resumes. Frequency determines
- how often you check the amount of free space (value is in
- seconds). Default settings are: 4, 2, and 30. That is, suspend
- accounting if there left <= 2% free; resume it if we have a value
- >=3%; consider information about the amount of free space valid
- for 30 seconds
+The file contains three values; highwater, lowwater, and frequency.
+
+It exists only when BSD-style process accounting is enabled. These values
+control its behavior. If the free space on the file system where the log lives
+goes below lowwater percentage, accounting suspends. If it goes above
+highwater percentage, accounting resumes. Frequency determines how often you
+check the amount of free space (value is in seconds). Default settings are: 4,
+2, and 30. That is, suspend accounting if there is less than 2 percent free;
+resume it if we have a value of 3 or more percent; consider information about
+the amount of free space valid for 30 seconds
ctrl-alt-del
- When the value in this file is 0, ctrl-alt-del is trapped and sent
- to the init(1) program to handle a graceful restart. However, when
- the value is > 0, Linux's reaction to this key combination will be
- an immediate reboot, without syncing its dirty buffers.
-
- Note: when a program (like dosemu) has the keyboard in raw mode,
- the ctrl-alt-del is intercepted by the program before it ever
- reaches the kernel tty layer, and it is up to the program to decide
- what to do with it.
+------------
+
+When the value in this file is 0, ctrl-alt-del is trapped and sent to the init
+program to handle a graceful restart. However, when the value is greater that
+zero, Linux's reaction to this key combination will be an immediate reboot,
+without syncing its dirty buffers.
+
+[NOTE]
+ When a program (like dosemu) has the keyboard in raw mode, the
+ ctrl-alt-del is intercepted by the program before it ever reaches the
+ kernel tty layer, and it is up to the program to decide what to do with
+ it.
domainname and hostname
- These files can be controlled to set the NIS domainname and
- hostname of your box. For the classic darkstar.frop.org a simple:
+-----------------------
+
+These files can be controlled to set the NIS domainname and hostname of your
+box. For the classic darkstar.frop.org a simple:
+
+ # echo "darkstar" > /proc/sys/kernel/hostname
+ # echo "frop.org" > /proc/sys/kernel/domainname
- # echo "darkstar" > /proc/sys/kernel/hostname
- # echo "frop.org" > /proc/sys/kernel/domainname
- would suffice to set your hostname and NIS domainname.
+would suffice to set your hostname and NIS domainname.
osrelease, ostype and version
+-----------------------------
- The names make it pretty obvious what these fields contain:
+The names make it pretty obvious what these fields contain:
- >cat /proc/sys/kernel/osrelease
- 2.1.131
- >cat /proc/sys/kernel/ostype
- Linux
- >cat /proc/sys/kernel/version
- #8 Mon Jan 25 19:45:02 PST 1999
-
- The files osrelease and ostype should be clear enough. Version
- needs a little more clarification however. The #8 means that this
- is the 8th kernel built from this source base and the date behind
- it indicates the time the kernel was built. The only way to tune
- these values is to rebuild the kernel.
-
-panic
- The value in this file represents the number of seconds the kernel
- waits before rebooting on a panic. When you use the software
- watchdog, the recommended setting is 60. If set to 0, the auto
- reboot after a kernel panic is disabled, this is the default
- setting.
+ > cat /proc/sys/kernel/osrelease
+ 2.2.12
+
+ > cat /proc/sys/kernel/ostype
+ Linux
+
+ > cat /proc/sys/kernel/version
+ #4 Fri Oct 1 12:41:14 PDT 1999
+
+
+The files osrelease and ostype should be clear enough. Version needs a little
+more clarification. The #4 means that this is the 4th kernel built from this
+source base and the date after it indicates the time the kernel was built. The
+only way to tune these values is to rebuild the kernel.
+
+panic
+-----
+
+The value in this file represents the number of seconds the kernel waits
+before rebooting on a panic. When you use the software watchdog, the
+recommended setting is 60. If set to 0, the auto reboot after a kernel panic
+is disabled, which is the default setting.
printk
- The four values in printk denote console_loglevel,
- default_message_loglevel, minimum_console_level, and
- default_console_loglevel respectively.
-
- These values influence printk() behavior when printing or logging
- error messages, which come from inside the kernel. See syslog(2)
- for more information on the different log levels.
-
- console_loglevel
- Messages with a higher priority than this will be printed to
- the console.
-
- default_message_level
- Messages without an explicit priority will be printed with
- this priority.
+------
+
+The four values in printk denote
+* console_loglevel,
+* default_message_loglevel,
+* minimum_console_level and
+* default_console_loglevel
+respectively.
+
+These values influence printk() behavior when printing or logging error
+messages, which come from inside the kernel. See syslog(2) for more
+information on the different log levels.
+
+console_loglevel
+----------------
+
+Messages with a higher priority than this will be printed to the console.
+
+default_message_level
+---------------------
+
+Messages without an explicit priority will be printed with this priority.
+
+minimum_console_loglevel
+------------------------
+
+Minimum (highest) value to which the console_loglevel can be set.
- minimum_console_loglevel
- Minimum (highest) value to which the console_loglevel can be set.
+default_console_loglevel
+------------------------
- default_console_loglevel
- Default value for console_loglevel.
+Default value for console_loglevel.
sg-big-buff
- This file shows the size of the generic SCSI (sg) buffer. At this
- point, you can't tune it yet, but you can change it at compile time
- by editing include/scsi/sg.h and changing the value of
- SG_BIG_BUFF.
-
- If you use a scanner with SANE (Scanner Access now easy) you
- might want to set this to a higher value. Look into the SANE
- documentation on this issue.
+-----------
+
+This file shows the size of the generic SCSI (sg) buffer. At this point, you
+can't tune it yet, but you can change it at compile time by editing
+include/scsi/sg.h and changing the value of SG_BIG_BUFF.
+
+If you use a scanner with SANE (Scanner Access Now Easy) you might want to set
+this to a higher value. Refer to the SANE documentation on this issue.
modprobe
- The location where the modprobe binary is located. The kernel
- uses this program to load modules on demand.
+--------
+
+The location where the modprobe binary is located. The kernel uses this
+program to load modules on demand.
-3.5 /proc/sys/vm - The virtual memory subsystem
+2.4 /proc/sys/vm - The virtual memory subsystem
+-----------------------------------------------
-The files in this directory can be used to tune the operation of the
-virtual memory (VM) subsystem of the Linux kernel. In addition, one of
-the files (bdflush) has a little influence on disk usage.
+The files in this directory can be used to tune the operation of the virtual
+memory (VM) subsystem of the Linux kernel. In addition, one of the files
+(bdflush) has some influence on disk usage.
bdflush
- This file controls the operation of the bdflush kernel daemon. It
- currently contains 9 integer values, 6 of which are actually used
- by the kernel:
-
- nfract Percentage of buffer cache dirty to
- activate bdflush
- ndirty Maximum number of dirty blocks to
- write out per-wake-cycle
- nrefill Number of clean buffers to try to obtain
- each time we call refill
- nref_dirt Dirty buffer threshold for activating bdflush
- when trying to refill buffers.
- dummy unused
- age_buffer Time for normal buffer to age before you flush it
- age_super Time for superblock to age before you flush it
- dummy unused
- dummy unused
-
- nfract
- This parameter governs the maximum number of dirty buffers
- in the buffer cache. Dirty means that the contents of the
- buffer still have to be written to disk (as opposed to a
- clean buffer, which can just be forgotten about). Setting
- this to a high value means that Linux can delay disk writes
- for a long time, but it also means that it will have to do a
- lot of I/O at once when memory becomes short. A low value
- will spread out disk I/O more evenly.
-
- ndirty
- Ndirty gives the maximum number of dirty buffers that
- bdflush can write to the disk at one time. A high value will
- mean delayed, bursty I/O, while a small value can lead to
- memory shortage when bdflush isn't woken up often enough.
-
- nrefill
- This the number of buffers that bdflush will add to the list
- of free buffers when refill_freelist() is called. It is
- necessary to allocate free buffers beforehand, since the
- buffers are often different sizes than the memory pages
- and some bookkeeping needs to be done beforehand. The
- higher the number, the more memory will be wasted and the
- less often refill_freelist() will need to run.
-
- nref_dirt
- When refill_freelist() comes across more than nref_dirt
- dirty buffers, it will wake up bdflush.
-
- age_buffer and age_super
- Finally, the age_buffer and age_super parameters govern the
- maximum time Linux waits before writing out a dirty buffer
- to disk. The value is expressed in jiffies (clockticks), the
- number of jiffies per second is 100. Age_buffer is the
- maximum age for data blocks, while age_super is for
- filesystems meta data.
+-------
+
+This file controls the operation of the bdflush kernel daemon. It currently
+contains nine integer values, six of which are actually used by the kernel.
+They are listed in table 2-2.
+
+
+Table 2-2: Parameters in /proc/sys/vm/bdflush
+..............................................................................
+ Value Meaning
+ nfract Percentage of buffer cache dirty to activate bdflush
+ ndirty Maximum number of dirty blocks to write out per wake-cycle
+ nrefill Number of clean buffers to try to obtain each time we call refill
+ nref_dirt buffer threshold for activating bdflush when trying to refill
+ buffers.
+ dummy Unused
+ age_buffer Time for normal buffer to age before we flush it
+ age_super Time for superblock to age before we flush it
+ dummy Unused
+ dummy Unused
+..............................................................................
+
+nfract
+------
+
+This parameter governs the maximum number of dirty buffers in the buffer
+cache. Dirty means that the contents of the buffer still have to be written to
+disk (as opposed to a clean buffer, which can just be forgotten about).
+Setting this to a higher value means that Linux can delay disk writes for a
+long time, but it also means that it will have to do a lot of I/O at once when
+memory becomes short. A lower value will spread out disk I/O more evenly.
+
+ndirty
+------
+
+Ndirty gives the maximum number of dirty buffers that bdflush can write to the
+disk at one time. A high value will mean delayed, bursty I/O, while a small
+value can lead to memory shortage when bdflush isn't woken up often enough.
+
+nrefill
+-------
+
+This is the number of buffers that bdflush will add to the list of free
+buffers when refill_freelist() is called. It is necessary to allocate free
+buffers beforehand, since the buffers are often different sizes than the
+memory pages and some bookkeeping needs to be done beforehand. The higher the
+number, the more memory will be wasted and the less often refill_freelist()
+will need to run.
+
+nref_dirt
+---------
+
+When refill_freelist() comes across more than nref_dirt dirty buffers, it will
+wake up bdflush.
+
+age_buffer and age_super
+------------------------
+
+Finally, the age_buffer and age_super parameters govern the maximum time Linux
+waits before writing out a dirty buffer to disk. The value is expressed in
+jiffies (clockticks), the number of jiffies per second is 100. Age_buffer is
+the maximum age for data blocks, while age_super is for filesystems meta data.
buffermem
- The three values in this file control how much memory should be
- used for buffer memory. The percentage is calculated as a
- percentage of total system memory.
-
- The values are:
-
- min_percent
- This is the minimum percentage of memory that should be
- spent on buffer memory.
-
- borrow_percent
- When Linux is short on memory, and the buffer cache uses more
- than it has been allotted, the memory mangement (MM) subsystem
- will prune the buffer cache more heavily than other memory to
- compensate.
-
- max_percent
- This is the maximum amount of memory that can be used for
- buffer memory.
+---------
+
+The three values in this file control how much memory should be used for
+buffer memory. The percentage is calculated as a percentage of total system
+memory.
+
+The values are:
+
+min_percent
+-----------
+
+This is the minimum percentage of memory that should be spent on buffer
+memory.
+
+borrow_percent
+--------------
+
+When Linux is short on memory, and the buffer cache uses more than it has been
+allotted, the memory management (MM) subsystem will prune the buffer cache
+more heavily than other memory to compensate.
+
+max_percent
+-----------
+
+This is the maximum amount of memory that can be used for buffer memory.
freepages
- This file contains three values: min, low and high:
+---------
+
+This file contains three values: min, low and high:
- min
- When the number of free pages in the system reaches this number,
- only the kernel can allocate more memory.
-
- low
- If the number of free pages gets below this point, the kernel
- starts swapping aggressively.
-
- high
- The kernel tries to keep up to this amount of memory free; if
- memory comes below this point, the kernel gently starts swapping
- in the hopes that it never has to do really aggressive swapping.
+min
+---
+When the number of free pages in the system reaches this number, only the
+kernel can allocate more memory.
+
+low
+---
+If the number of free pages falls below this point, the kernel starts swapping
+aggressively.
+
+high
+----
+The kernel tries to keep up to this amount of memory free; if memory falls
+below this point, the kernel starts gently swapping in the hopes that it never
+has to do really aggressive swapping.
kswapd
- Kswapd is the kernel swap out daemon. That is, kswapd is that piece
- of the kernel that frees memory when it gets fragmented or
- full. Since every system is different, you'll probably want some
- control over this piece of the system.
-
- The file contains three numbers:
-
- tries_base
- The maximum number of pages kswapd tries to free in one round is
- calculated from this number. Usually this number will be divided
- by 4 or 8 (see mm/vmscan.c), so it isn't as big as it looks.
-
- When you need to increase the bandwidth to/from swap, you'll want
- to increase this number.
-
- tries_min
- This is the minimum number of times kswapd tries to free a page
- each time it is called. Basically it's just there to make sure
- that kswapd frees some pages even when it's being called with
- minimum priority.
-
-
- swap_cluster
- This is probably the greatest influence on system
- performance. swap_cluster is the number of pages kswapd writes in
- one turn. You'll want this value to be large so that kswapd does
- its I/O in large chunks and the disk doesn't have to seek as
- often., but you don't want it to be too large since that would
- flood the request queue.
+------
+
+Kswapd is the kernel swap out daemon. That is, kswapd is that piece of the
+kernel that frees memory when it gets fragmented or full. Since every system
+is different, you'll probably want some control over this piece of the system.
+
+The file contains three numbers:
+
+tries_base
+----------
+
+The maximum number of pages kswapd tries to free in one round is calculated
+from this number. Usually this number will be divided by 4 or 8 (see
+mm/vmscan.c), so it isn't as big as it looks.
+
+When you need to increase the bandwidth to/from swap, you'll want to increase
+this number.
+
+tries_min
+---------
+
+This is the minimum number of times kswapd tries to free a page each time it
+is called. Basically it's just there to make sure that kswapd frees some pages
+even when it's being called with minimum priority.
+
+swap_cluster
+------------
+
+This is probably the greatest influence on system performance.
+
+swap_cluster is the number of pages kswapd writes in one turn. You'll want
+this value to be large so that kswapd does its I/O in large chunks and the
+disk doesn't have to seek as often, but you don't want it to be too large
+since that would flood the request queue.
overcommit_memory
- This file contains one value. The following algorithm is used to
- decide if there's enough memory: if the value of overcommit_memory
- is positive, then there's always enough memory. This is a useful
- feature, since programs often malloc() huge amounts of memory 'just
- in case', while they only use a small part of it. Leaving this
- value at 0 will lead to the failure of such a huge malloc(), when
- in fact the system has enough memory for the program to run.
-
- On the other hand, enabling this feature can cause you to run out
- of memory and thrash the system to death, so large and/or important
- servers will want to set this value to 0.
+-----------------
+
+This file contains one value. The following algorithm is used to decide if
+there's enough memory: if the value of overcommit_memory is positive, then
+there's always enough memory. This is a useful feature, since programs often
+malloc() huge amounts of memory 'just in case', while they only use a small
+part of it. Leaving this value at 0 will lead to the failure of such a huge
+malloc(), when in fact the system has enough memory for the program to run.
+
+On the other hand, enabling this feature can cause you to run out of memory
+and thrash the system to death, so large and/or important servers will want to
+set this value to 0.
pagecache
- This file does exactly the same as buffermem, only this file
- controls the amount of memory allowed for memory mapping and
- generic caching of files.
-
- You don't want the minimum level to be too low, otherwise your
- system might thrash when memory is tight or fragmentation is
- high.
+---------
+
+This file does exactly the same job as buffermem, only this file controls the
+amount of memory allowed for memory mapping and generic caching of files.
+
+You don't want the minimum level to be too low, otherwise your system might
+thrash when memory is tight or fragmentation is high.
pagetable_cache
- The kernel keeps a number of page tables in a per-processor cache
- (this helps a lot on SMP systems). The cache size for each
- processor will be between the low and the high value.
-
- On a low-memory, single CPU system, you can safely set these values
- to 0 so you don't waste memory. It is used on SMP systems so that
- the system can perform fast pagetable allocations without having to
- aquire the kernel memory lock.
-
- For large systems, the settings are probably fine. For normal
- systems they won't hurt a bit. For small systems (<16MB ram) it
- might be advantageous to set both values to 0.
+---------------
+
+The kernel keeps a number of page tables in a per-processor cache (this helps
+a lot on SMP systems). The cache size for each processor will be between the
+low and the high value.
+
+On a low-memory, single CPU system, you can safely set these values to 0 so
+you don't waste memory. It is used on SMP systems so that the system can
+perform fast pagetable allocations without having to aquire the kernel memory
+lock.
+
+For large systems, the settings are probably fine. For normal systems they
+won't hurt a bit. For small systems ( less than 16MB ram) it might be
+advantageous to set both values to 0.
swapctl
- This file contains no less than 8 variables. All of these values
- are used by kswapd.
+-------
+
+This file contains no less than 8 variables. All of these values are used by
+kswapd.
- The first four variables sc_max_page_age, sc_page_advance,
- sc_page_decline and sc_page_initial_age are used to keep track of
- Linux's page aging. Page aging is a bookkeeping method to track
- which pages of memory are often used, and which pages can be
- swapped out without consequences.
-
- When a page is swapped in, it starts at sc_page_initial_age
- (default 3) and when the page is scanned by kswapd, its age is
- adjusted according to the following scheme:
-
- o If the page was used since the last time we scanned, its age
- is increased by sc_page_advance (default 3) up to a
- maximum of sc_max_page_age (default 20).
-
- o Else (meaning it wasn't used) its age is decreased by
- sc_page_decline (default 1).
-
- When a page reaches age 0, it's ready to be swapped out.
-
- The next four variables sc_age_cluster_fract, sc_age_cluster_min,
- sc_pageout_weight and sc_bufferout_weight, can be used to control
- kswapd's aggressiveness in swapping out pages.
-
- Sc_age_cluster_fract is used to calculate how many pages from a
- process are to be scanned by kswapd. The formula used is
-
- sc_age_cluster_fract
- -------------------- * resident set size
- 1024 =20
-
- So if you want kswapd to scan the whole process,
- sc_age_cluster_fract needs to have a value of 1024. The minimum
- number of pages kswapd will scan is represented by
- sc_age_cluster_min, this is done so kswapd will also scan small
- processes.
-
- The values of sc_pageout_weight and sc_bufferout_weight are used
- to control how many tries kswapd will make in order to swap out
- one page/buffer. These values can be used to fine-tune the ratio
- between user pages and buffer/cache memory. When you find that
- your Linux system is swapping out too many process pages in order
- to satisfy buffer memory demands, you might want to either
- increase sc_bufferout_weight, or decrease the value of
- sc_pageout_weight.
-
-3.6 /proc/sys/dev - Device specific parameters
-
-Currently there is only support for CDROM drives, but other drivers may
-wish to register themselves in here in the future. The cdrom/ directory
-contains several files that either control or supply information about
-the CDROM subsystem.
-
->cat /proc/sys/dev/cdrom/info
-CD-ROM information, Id: cdrom.c 3.04 1999/09/12
-
-drive name: hdd hdc hdb hda
-drive speed: 32 24 10 0
-drive # of slots: 1 1 1 1
-Can close tray: 1 1 1 1
-Can open tray: 1 1 1 1
-Can lock tray: 1 1 1 1
-Can change speed: 1 1 1 1
-Can select disk: 0 0 0 0
-Can read multisession: 1 1 1 1
-Can read MCN: 1 1 1 1
-Reports media changed: 1 1 1 1
-Can play audio: 1 1 1 1
-Can write CD-R: 0 1 0 0
-Can write CD-RW: 0 1 0 0
-Can read DVD: 0 0 0 1
-Can write DVD-R: 0 0 0 0
-Can write DVD-RAM: 0 0 0 0
-
-You see four drives and their lists of features. These are all ATAPI
-drives - SCSI drives will be numbered sr0, sr1, and so forth.
-
-The remaining files all set options in the driver.
-
-autoclose
- Close the drive tray when the drive is accessed.
-
-autoeject
- Eject the tray when the drive is umounted.
-
-check_media
- Verify the media type when opening the device. This is generally
- meant for audio CD's.
-
-debug
- Print debugging messages.
-
-lock
- Lock the tray when the drive is in use.
-
-
-3.7 /proc/sys/sunrpc - Remote procedure calls
-
-This directory contains four files, which enable or disable debugging
-for the RPC functions NFS, NFS-daemon, RPC and NLM. The default values
-are 0. They can be set to one, to turn debugging on. (The default
-value is 0 for each)
-
-3.8 /proc/sys/net - Networking stuff
-
-The interface to the networking parts of the kernel is located in
-/proc/sys/net. The table below shows all possible subdirectories. You
-may see only some of them, depending on the configuration of your
-kernel:
-
-+-------------------------------------------------------------+
-| core General parameter |appletalk Appletalk protocol |
-| unix Unix domain sockets |netrom NET/ROM |
-| 802 E802 protocol |ax25 AX25 |
-| ethernet Ethernet protocol |rose X.25 PLP layer |
-| ipv4 IP version 4 |x25 X.25 protocol |
-| ipx IPX |token-ring IBM token ring |
-| bridge Bridging |decnet DEC net |
-| ipv6 IP version 6 | |
-+-------------------------------------------------------------+
-
-We will concentrate on IP networking here. As AX15, X.25, and DEC Net
-are only minor players in the Linux world, we'll skip them in this
-chapter. You'll find some short info to Appletalk and IPX further down
-in section 3.10 and 3.11. Please look in the online documentation and
-the kernel source to get a detailed view of the parameters for those
-protocols. In this section we'll discuss the subdirectories printed in
-bold letters in the table above. As default values are suitable for
-most needs, there is no need to change these values.
+The first four variables
+* sc_max_page_age,
+* sc_page_advance,
+* sc_page_decline and
+* sc_page_initial_age
+are used to keep track of Linux's page aging. Page aging is a bookkeeping
+method to track which pages of memory are often used, and which pages can be
+swapped out without consequences.
+
+When a page is swapped in, it starts at sc_page_initial_age (default 3) and
+when the page is scanned by kswapd, its age is adjusted according to the
+following scheme:
+
+* If the page was used since the last time we scanned, its age is increased
+ by sc_page_advance (default 3). Where the maximum value is given by
+ sc_max_page_age (default 20).
+* Otherwise (meaning it wasn't used) its age is decreased by sc_page_decline
+ (default 1).
+
+When a page reaches age 0, it's ready to be swapped out.
+
+The variables sc_age_cluster_fract, sc_age_cluster_min, sc_pageout_weight and
+sc_bufferout_weight, can be used to control kswapd's aggressiveness in
+swapping out pages.
+
+Sc_age_cluster_fract is used to calculate how many pages from a process are to
+be scanned by kswapd. The formula used is
+
+(sc_age_cluster_fract divided by 1024) times resident set size
+
+So if you want kswapd to scan the whole process, sc_age_cluster_fract needs to
+have a value of 1024. The minimum number of pages kswapd will scan is
+represented by sc_age_cluster_min, which is done so that kswapd will also scan
+small processes.
+
+The values of sc_pageout_weight and sc_bufferout_weight are used to control
+how many tries kswapd will make in order to swap out one page/buffer. These
+values can be used to fine-tune the ratio between user pages and buffer/cache
+memory. When you find that your Linux system is swapping out too many process
+pages in order to satisfy buffer memory demands, you may want to either
+increase sc_bufferout_weight, or decrease the value of sc_pageout_weight.
+
+2.5 /proc/sys/dev - Device specific parameters
+----------------------------------------------
+
+Currently there is only support for CDROM drives, and for those, there is only
+one read-only file containing information about the CD-ROM drives attached to
+the system:
+
+ >cat /proc/sys/dev/cdrom/info
+ CD-ROM information, Id: cdrom.c 2.55 1999/04/25
+
+ drive name: sr0 hdb
+ drive speed: 32 40
+ drive # of slots: 1 0
+ Can close tray: 1 1
+ Can open tray: 1 1
+ Can lock tray: 1 1
+ Can change speed: 1 1
+ Can select disk: 0 1
+ Can read multisession: 1 1
+ Can read MCN: 1 1
+ Reports media changed: 1 1
+ Can play audio: 1 1
+
+
+You see two drives, sr0 and hdb, along with a list of their features.
+
+2.6 /proc/sys/sunrpc - Remote procedure calls
+---------------------------------------------
+
+This directory contains four files, which enable or disable debugging for the
+RPC functions NFS, NFS-daemon, RPC and NLM. The default values are 0. They can
+be set to one to turn debugging on. (The default value is 0 for each)
+
+2.7 /proc/sys/net - Networking stuff
+------------------------------------
+
+The interface to the networking parts of the kernel is located in
+/proc/sys/net. Table 2-3 shows all possible subdirectories. You may see only
+some of them, depending on your kernel's configuration.
+
+
+Table 2-3: Subdirectories in /proc/sys/net
+..............................................................................
+ Directory Content Directory Content
+ core General parameter appletalk Appletalk protocol
+ unix Unix domain sockets netrom NET/ROM
+ 802 E802 protocol ax25 AX25
+ ethernet Ethernet protocol rose X.25 PLP layer
+ ipv4 IP version 4 x25 X.25 protocol
+ ipx IPX token-ring IBM token ring
+ bridge Bridging decnet DEC net
+ ipv6 IP version 6
+..............................................................................
+
+We will concentrate on IP networking here. Since AX15, X.25, and DEC Net are
+only minor players in the Linux world, we'll skip them in this chapter. You'll
+find some short info on Appletalk and IPX further on in this chapter. Review
+the online documentation and the kernel source to get a detailed view of the
+parameters for those protocols. In this section we'll discuss the
+subdirectories printed in bold letters in the table above. As default values
+are suitable for most needs, there is no need to change these values.
/proc/sys/net/core - Network core options
+-----------------------------------------
rmem_default
- The default setting of the socket receive buffer in bytes.
+------------
+
+The default setting of the socket receive buffer in bytes.
rmem_max
- The maximum receive socket buffer size in bytes.
+--------
+
+The maximum receive socket buffer size in bytes.
wmem_default
- The default setting (in bytes) of the socket send buffer.
+------------
+
+The default setting (in bytes) of the socket send buffer.
wmem_max
- The maximum send socket buffer size in bytes.
+--------
+
+The maximum send socket buffer size in bytes.
message_burst and message_cost
- These parameters are used to limit the warning messages written to
- the kernel log from the networking code. They enforce a rate limit
- to make a denial-of-service attack impossible. The higher the
- message_cost factor is, the less messages will be
- written. Message_burst controls when messages will be dropped. The
- default settings limit warning messages to one every five seconds.
+------------------------------
+
+These parameters are used to limit the warning messages written to the kernel
+log from the networking code. They enforce a rate limit to make a
+denial-of-service attack impossible. A higher message_cost factor, results in
+fewer messages that will be written. Message_burst controls when messages will
+be dropped. The default settings limit warning messages to one every five
+seconds.
netdev_max_backlog
- Maximal number of packets, queued on INPUT side, when the interface
- receives packets faster than kernel can process them.
+------------------
+
+Maximum number of packets, queued on the INPUT side, when the interface
+receives packets faster than kernel can process them.
optmem_max
- Maximum ancillary buffer size allowed per socket. Ancillary data is
- a sequence of struct cmsghdr structures with appended data.
+----------
-/proc/sys/net/unix - Parameters for UNIX domain sockets
+Maximum ancillary buffer size allowed per socket. Ancillary data is a sequence
+of struct cmsghdr structures with appended data.
-There are only two files in this subdirectory. They control the delays
-for deleting and destroying socket descriptors.
+/proc/sys/net/unix - Parameters for Unix domain sockets
+-------------------------------------------------------
-3.9 /proc/sys/net/ipv4 - IPV4 settings
+There are only two files in this subdirectory. They control the delays for
+deleting and destroying socket descriptors.
-IP version 4 is still the most used protocol in Unix networking. It
-will be replaced by IP version 6 in the next couple of years, but for
-the moment it's the de facto standard for the internet and is used in
-most networking environments around the world. Because of the
-importance of this protocol, we'll have a deeper look into the subtree
-controlling the behavior of the IPv4 subsystem of the Linux kernel.
+2.8 /proc/sys/net/ipv4 - IPV4 settings
+--------------------------------------
-Let's start with the entries in /proc/sys/net/ipv4 itself.
+IP version 4 is still the most used protocol in Unix networking. It will be
+replaced by IP version 6 in the next couple of years, but for the moment it's
+the de facto standard for the internet and is used in most networking
+environments around the world. Because of the importance of this protocol,
+we'll have a deeper look into the subtree controlling the behavior of the IPv4
+subsystem of the Linux kernel.
+
+Let's start with the entries in /proc/sys/net/ipv4.
ICMP settings
+-------------
icmp_echo_ignore_all and icmp_echo_ignore_broadcasts
- Turn on (1) or off (0), if the kernel should ignore all ICMP ECHO
- requests, or just those to broadcast and multicast addresses.
+----------------------------------------------------
+
+Turn on (1) or off (0), if the kernel should ignore all ICMP ECHO requests, or
+just those to broadcast and multicast addresses.
+
+Please note that if you accept ICMP echo requests with a broadcast/multi\-cast
+destination address your network may be used as an exploder for denial of
+service packet flooding attacks to other hosts.
- Please note that if you accept ICMP echo requests with a
- broadcast/multicast destination address your network may be used
- as an exploder for denial of service packet flooding attacks to
- other hosts.
-
-icmp_destunreach_rate, icmp_echoreply_rate,
-icmp_paramprob_rate and icmp_timeexeed_rate
- Sets limits for sending ICMP packets to specific targets. A value of
- zero disables all limiting. Any positive value sets the maximum
- package rate in hundredths of a second (on Intel systems).
+icmp_destunreach_rate, icmp_echoreply_rate, icmp_paramprob_rate and icmp_timeexeed_rate
+---------------------------------------------------------------------------------------
+
+Sets limits for sending ICMP packets to specific targets. A value of zero
+disables all limiting. Any positive value sets the maximum package rate in
+hundredth of a second (on Intel systems).
IP settings
+-----------
ip_autoconfig
- This file contains one, if the host got its IP configuration by
- RARP, BOOTP, DHCP or a similar mechanism. Otherwise it is zero.
+-------------
+
+This file contains the number one if the host received its IP configuration by
+RARP, BOOTP, DHCP or a similar mechanism. Otherwise it is zero.
ip_default_ttl
- TTL (Time To Live) for IPv4 interfaces. This is simply the
- maximum number of hops a packet may travel.
+--------------
+
+TTL (Time To Live) for IPv4 interfaces. This is simply the maximum number of
+hops a packet may travel.
ip_dynaddr
- Enable dynamic socket address rewriting on interface address change. This
- is useful for dialup interface with changing IP addresses.
+----------
+
+Enable dynamic socket address rewriting on interface address change. This is
+useful for dialup interface with changing IP addresses.
ip_forward
- Enable or disable forwarding of IP packages between interfaces. A
- change of this value resets all other parameters to their default
- values. They differ if the kernel is configured as host or router.
+----------
+
+Enable or disable forwarding of IP packages between interfaces. Changing this
+value resets all other parameters to their default values. They differ if the
+kernel is configured as host or router.
ip_local_port_range
- Range of ports used by TCP and UDP to choose the local
- port. Contains two numbers, the first number is the lowest port,
- the second number the highest local port. Default is 1024-4999.
- Should be changed to 32768-61000 for high-usage systems.
+-------------------
+
+Range of ports used by TCP and UDP to choose the local port. Contains two
+numbers, the first number is the lowest port, the second number the highest
+local port. Default is 1024-4999. Should be changed to 32768-61000 for
+high-usage systems.
ip_no_pmtu_disc
- Global switch to turn path MTU discovery off. It can also be set
- on a per socket basis by the applications or on a per route
- basis.
+---------------
+
+Global switch to turn path MTU discovery off. It can also be set on a per
+socket basis by the applications or on a per route basis.
ip_masq_debug
- Enable/disable debugging of IP masquerading.
+-------------
+Enable/disable debugging of IP masquerading.
IP fragmentation settings
+-------------------------
ipfrag_high_trash and ipfrag_low_trash
- Maximum memory used to reassemble IP fragments. When
- ipfrag_high_thresh bytes of memory is allocated for this purpose,
- the fragment handler will toss packets until ipfrag_low_thresh is
- reached.
+--------------------------------------
+Maximum memory used to reassemble IP fragments. When ipfrag_high_thresh bytes
+of memory is allocated for this purpose, the fragment handler will toss
+packets until ipfrag_low_thresh is reached.
ipfrag_time
- Time in seconds to keep an IP fragment in memory.
+-----------
+
+Time in seconds to keep an IP fragment in memory.
TCP settings
+------------
tcp_retrans_collapse
- Bug-to-bug compatibility with some broken printers. On retransmit
- try to send bigger packets to work around bugs in certain TCP
- stacks. Can be turned off by setting it to zero.
+--------------------
+
+Bug-to-bug compatibility with some broken printers. On retransmit, try to send
+larger packets to work around bugs in certain TCP stacks. Can be turned off by
+setting it to zero.
tcp_keepalive_probes
- Number of keep alive probes TCP sends out, until it decides that the
- connection is broken.
+--------------------
+
+Number of keep alive probes TCP sends out, until it decides that the
+connection is broken.
tcp_keepalive_time
- How often TCP sends out keep alive messages, when keep alive is
- enabled. The default is 2 hours.
+------------------
+
+How often TCP sends out keep alive messages, when keep alive is enabled. The
+default is 2 hours.
tcp_syn_retries
- Number of times initial SYNs for a TCP connection attempt will be
- retransmitted. Should not be higher than 255. This is only the
- timeout for outgoing connections, for incoming connections the
- number of retransmits is defined by tcp_retries1.
+---------------
+
+Number of times initial SYNs for a TCP connection attempt will be
+retransmitted. Should not be higher than 255. This is only the timeout for
+outgoing connections, for incoming connections the number of retransmits is
+defined by tcp_retries1.
tcp_sack
- Enable select acknowledgments after RFC2018.
+--------
+
+Enable select acknowledgments after RFC2018.
tcp_timestamps
- Enable timestamps as defined in RFC1323.
+--------------
+
+Enable timestamps as defined in RFC1323.
tcp_stdurg
- Enable the strict RFC793 interpretation of the TCP urgent pointer
- field. The default is to use the BSD compatible interpretation
- of the urgent pointer pointing to the first byte after the urgent
- data. The RFC793 interpretation is to have it point to the last
- byte of urgent data. Enabling this option may lead to
- interoperatibility problems. Disabled by default.
+----------
+
+Enable the strict RFC793 interpretation of the TCP urgent pointer field. The
+default is to use the BSD compatible interpretation of the urgent pointer
+pointing to the first byte after the urgent data. The RFC793 interpretation is
+to have it point to the last byte of urgent data. Enabling this option may
+lead to interoperatibility problems. Disabled by default.
tcp_syncookies
- Only valid when the kernel was compiled with
- CONFIG_SYNCOOKIES. Send out syncookies when the syn backlog queue
- of a socket overflows. This is to prevent against the common 'syn
- flood attack'. Disabled by default.
-
- Note that the concept of a socket backlog is abandoned, this
- means the peer may not receive reliable error messages from an
- over loaded server with syncookies enabled.
+--------------
+
+Only valid when the kernel was compiled with CONFIG_SYNCOOKIES. Send out
+syncookies when the syn backlog queue of a socket overflows. This is to ward
+off the common 'syn flood attack'. Disabled by default.
+
+Note that the concept of a socket backlog is abandoned. This means the peer
+may not receive reliable error messages from an over loaded server with
+syncookies enabled.
tcp_window_scaling
- Enable window scaling as defined in RFC1323.
+------------------
+
+Enable window scaling as defined in RFC1323.
tcp_fin_timeout
- How many seconds to wait for a final FIN before the socket is
- always closed. This is strictly a violation of the TCP
- specification, but required to prevent denial-of-service attacks.
+---------------
+
+The length of time in seconds it takes to receive a final FIN before the
+socket is always closed. This is strictly a violation of the TCP
+specification, but required to prevent denial-of-service attacks.
tcp_max_ka_probes
- How many keepalive probes are sent per slow timer run. Shouldn't be
- set too high to prevent bursts.
+-----------------
+
+Indicates how many keep alive probes are sent per slow timer run. Should not
+be set too high to prevent bursts.
tcp_max_syn_backlog
- Length of the per socket backlog queue. Since Linux 2.2 the backlog
- specified in listen(2) only specifies the length of the backlog
- queue of already established sockets. When more connection requests
- arrive Linux starts to drop packets. When syncookies are enabled
- the packets are still answered and the maximum queue is effectively
- ignored.
+-------------------
+
+Length of the per socket backlog queue. Since Linux 2.2 the backlog specified
+in listen(2) only specifies the length of the backlog queue of already
+established sockets. When more connection requests arrive Linux starts to drop
+packets. When syncookies are enabled the packets are still answered and the
+maximum queue is effectively ignored.
tcp_retries1
- Defines how often an answer to a TCP connection request is
- retransmitted before giving up.
+------------
+
+Defines how often an answer to a TCP connection request is retransmitted
+before giving up.
tcp_retries2
- Defines how often a TCP packet is retransmitted before giving up.
+------------
-Interface specific settings
+Defines how often a TCP packet is retransmitted before giving up.
-In the directory /proc/sys/net/ipv4/conf you'll find one subdirectory
-for each interface the system knows about and one directory calls
-all. Changes in the all subdirectory affect all interfaces, where
-changes in the other subdirectories affect only one interface.
+Interface specific settings
+---------------------------
-All directories have the same entries:
+In the directory /proc/sys/net/ipv4/conf you'll find one subdirectory for each
+interface the system knows about and one directory calls all. Changes in the
+all subdirectory affect all interfaces, whereas changes in the other
+subdirectories affect only one interface. All directories have the same
+entries:
accept_redirects
- This switch decides if the kernel accepts ICMP redirect messages
- or not. The default is 'yes', if the kernel is configured for a
- regular host; and 'no' for a router configuration.
+----------------
+
+This switch decides if the kernel accepts ICMP redirect messages or not. The
+default is 'yes' if the kernel is configured for a regular host and 'no' for a
+router configuration.
accept_source_route
- Should source routed packages be accepted or declined. The
- default is dependent on the kernel configuration. It's 'yes' for
- routers and 'no' for hosts.
+-------------------
+
+Should source routed packages be accepted or declined. The default is
+dependent on the kernel configuration. It's 'yes' for routers and 'no' for
+hosts.
bootp_relay
- Accept packets with source address 0.b.c.d destined not to this
- host as local ones. It is supposed that BOOTP relay daemon will
- catch and forward such packets.
+~~~~~~~~~~~
- The default is 'no', as this feature is not implemented yet
- (kernel version 2.2.0-pre?).
+Accept packets with source address 0.b.c.d with destinations not to this host
+as local ones. It is supposed that a BOOTP relay daemon will catch and forward
+such packets.
+
+The default is 0, since this feature is not implemented yet (kernel version
+2.2.12).
forwarding
- Enable or disable IP forwarding on this interface.
+----------
+
+Enable or disable IP forwarding on this interface.
log_martians
- Log packets with source addresses with no known route to kernel log.
+------------
+
+Log packets with source addresses with no known route to kernel log.
mc_forwarding
- Do multicast routing. The kernel needs to be compiled with
- CONFIG_MROUTE and a multicast routing daemon is required.
+-------------
+
+Do multicast routing. The kernel needs to be compiled with CONFIG_MROUTE and a
+multicast routing daemon is required.
proxy_arp
- Do (1) or don't (0) do proxy ARP.
+---------
+
+Does (1) or does not (0) perform proxy ARP.
rp_filter
- Integer value deciding if source validation should be made.
- 1 means yes, 0 means no. Disabled by default, but
- local/broadcast address spoofing is always on.
-
- If you set this to 1 on a router that is the only connection
- for a network to the net , it evidently prevents spoofing attacks
- against your internal networks (external addresses can still be
- spoofed), without the need for additional firewall rules.
+---------
+
+Integer value determines if a source validation should be made. 1 means yes, 0
+means no. Disabled by default, but local/broadcast address spoofing is always
+on.
+
+If you set this to 1 on a router that is the only connection for a network to
+the net, it will prevent spoofing attacks against your internal networks
+(external addresses can still be spoofed), without the need for additional
+firewall rules.
secure_redirects
- Accept ICMP redirect messages only for gateways, listed in
- default gateway list. Enabled by default.
+----------------
+
+Accept ICMP redirect messages only for gateways, listed in default gateway
+list. Enabled by default.
shared_media
- If it is not set the kernel does not assume that different subnets
- on this device can communicate directly. Default setting is 'yes'.
+------------
+
+If it is not set the kernel does not assume that different subnets on this
+device can communicate directly. Default setting is 'yes'.
send_redirects
- Determines if or if not to send ICMP redirects to other hosts.
+--------------
+Determines whether to send ICMP redirects to other hosts.
Routing settings
+----------------
-The directory /proc/sys/net/ipv4/route contains several file to
-control routing issues.
+The directory /proc/sys/net/ipv4/route contains several file to control
+routing issues.
error_burst and error_cost
- These parameters are used to limit the warning messages written to
- the kernel log from the routing code. The higher the error_cost
- factor is, the fewer messages will be written. Error_burst controls
- when messages will be dropped. The default settings limit warning
- messages to one every five seconds.
+--------------------------
+
+These parameters are used to limit the warning messages written to the kernel
+log from the routing code. The higher the error_cost factor is, the fewer
+messages will be written. Error_burst controls when messages will be dropped.
+The default settings limit warning messages to one every five seconds.
flush
- Writing to this file results in a flush of the routing cache.
+-----
+
+Writing to this file results in a flush of the routing cache.
gc_elastic, gc_interval, gc_min_interval, gc_tresh, gc_timeout
- Values to control the frequency and behavior of the garbage
- collection algorithm for the routing cache.
+--------------------------------------------------------------
+
+Values to control the frequency and behavior of the garbage collection
+algorithm for the routing cache.
max_size
- Maximum size of the routing cache. Old entries will be purged
- once the cache has this size.
+--------
+
+Maximum size of the routing cache. Old entries will be purged once the cache
+reached has this size.
max_delay, min_delay
- Delays for flushing the routing cache.
+--------------------
+
+Delays for flushing the routing cache.
redirect_load, redirect_number
- Factors which determine if more ICPM redirects should be sent to
- a specific host. No redirects will be sent once the load limit or
- the maximum number of redirects has been reached.
+------------------------------
+
+Factors which determine if more ICPM redirects should be sent to a specific
+host. No redirects will be sent once the load limit or the maximum number of
+redirects has been reached.
redirect_silence
+----------------
- Timeout for redirects. After this period redirects will be sent
- again, even if this has been stopped, because the load or number
- limit has been reached.
+Timeout for redirects. After this period redirects will be sent again, even if
+this has been stopped, because the load or number limit has been reached.
Network Neighbor handling
+-------------------------
+
+Settings about how to handle connections with direct neighbors (nodes attached
+to the same link) can be found in the directory /proc/sys/net/ipv4/neigh.
-Settings about how to handle connections with direct neighbors (nodes
-attached to the same link) can be found in the directory
-/proc/sys/net/ipv4/neigh.
-
-As we saw it in the conf directory, there is a default subdirectory
-which holds the default values, and one directory for each
-interface. The contents of the directories are identical, with the
-single exception that the default settings contain additional options
-to set garbage collection parameters.
+As we saw it in the conf directory, there is a default subdirectory which
+holds the default values, and one directory for each interface. The contents
+of the directories are identical, with the single exception that the default
+settings contain additional options to set garbage collection parameters.
In the interface directories you'll find the following entries:
base_reachable_time
- A base value used for computing the random reachable time value
- as specified in RFC2461.
+-------------------
+
+A base value used for computing the random reachable time value as specified
+in RFC2461.
retrans_time
- The time, expressed in jiffies (1/100 sec), between retransmitted
- Neighbor Solicitation messages. Used for address resolution and to
- determine if a neighbor is unreachable.
+------------
+
+The time, expressed in jiffies (1/100 sec), between retransmitted Neighbor
+Solicitation messages. Used for address resolution and to determine if a
+neighbor is unreachable.
unres_qlen
- Maximum queue length for a pending arp request - how many packets
- are accepted from other layers while the arp address is still
- resolved.
+----------
+
+Maximum queue length for a pending arp request - the number of packets which
+are accepted from other layers while the ARP address is still resolved.
anycast_delay
- Maximum for random delay of answers to neighbor solicitation
- messages in jiffies (1/100 sec). Not yet implemented (Linux does
- not have anycast support yet).
+-------------
+
+Maximum for random delay of answers to neighbor solicitation messages in
+jiffies (1/100 sec). Not yet implemented (Linux does not have anycast support
+yet).
ucast_solicit
- Maximum number of retries for unicast solicitation.
+-------------
+
+Maximum number of retries for unicast solicitation.
mcast_solicit
- Maximum number of retries for multicast solicitation.
+-------------
+
+Maximum number of retries for multicast solicitation.
delay_first_probe_time
- Delay for the first time probe if the neighbor is reachable. (see
- gc_stale_time).
+----------------------
+
+Delay for the first time probe if the neighbor is reachable. (see
+gc_stale_time)
locktime
- An ARP/neighbor entry is only replaced with a new one if the old
- is at least locktime old. This prevents ARP cache thrashing.
+--------
+
+An ARP/neighbor entry is only replaced with a new one if the old is at least
+locktime old. This prevents ARP cache thrashing.
proxy_delay
- Maximum time (real time is random [0..proxytime]) before
- answering to an arp request for which we have an proxy arp entry.
- In some cases, this is used to prevent network flooding.
+-----------
+
+Maximum time (real time is random [0..proxytime]) before answering to an ARP
+request for which we have an proxy ARP entry. In some cases, this is used to
+prevent network flooding.
proxy_qlen
- Maximum queue length of the delayed proxy arp timer (see
- proxy_delay).
+----------
+
+Maximum queue length of the delayed proxy arp timer. (see proxy_delay).
app_solcit
- Determines the number of requests to send to the user level arp
- daemon. 0 to turn off.
+----------
+
+Determines the number of requests to send to the user level ARP daemon. Use 0
+to turn off.
gc_stale_time
- Determines how often to check for stale ARP entries. After an ARP
- entry is stale it will be resolved again (useful when an IP address
- migrates to another machine). When ucast_solicit is > 0 it first
- tries to send an ARP packet directly to the known host, when that
- fails and mcast_solicit is > 0, an ARP request is broadcasted.
-
-3.10 Appletalk
-
-The /proc/sys/net/appletalk directory holds the Appletalk
-configuration data when Appletalk is loaded. The configurable
-parameters are:
+-------------
+
+Determines how often to check for stale ARP entries. After an ARP entry is
+stale it will be resolved again (which is useful when an IP address migrates
+to another machine). When ucast_solicit is greater than 0 it first tries to
+send an ARP packet directly to the known host When that fails and
+mcast_solicit is greater than 0, an ARP request is broadcasted.
+
+2.9 Appletalk
+-------------
+
+The /proc/sys/net/appletalk directory holds the Appletalk configuration data
+when Appletalk is loaded. The configurable parameters are:
aarp-expiry-time
- The amount of time we keep an AARP entry before expiring
- it. Used to age out old hosts.
+----------------
+
+The amount of time we keep an ARP entry before expiring it. Used to age out
+old hosts.
aarp-resolve-time
- The amount of time we will spend trying to resolve an Appletalk
- address.
+-----------------
+
+The amount of time we will spend trying to resolve an Appletalk address.
aarp-retransmit-limit
- The number of times we will retransmit a query before giving up.
+---------------------
+
+The number of times we will retransmit a query before giving up.
aarp-tick-time
- Controls the rate at which expiries are checked.
+--------------
+
+Controls the rate at which expires are checked.
+
+The directory /proc/net/appletalk holds the list of active Appletalk sockets
+on a machine.
+
+The fields indicate the DDP type, the local address (in network:node format)
+the remote address, the size of the transmit pending queue, the size of the
+received queue (bytes waiting for applications to read) the state and the uid
+owning the socket.
+
+/proc/net/atalk_iface lists all the interfaces configured for appletalk.It
+shows the name of the interface, its Appletalk address, the network range on
+that address (or network number for phase 1 networks), and the status of the
+interface.
+
+/proc/net/atalk_route lists each known network route. It lists the target
+(network) that the route leads to, the router (may be directly connected), the
+route flags, and the device the route is using.
+
+2.10 IPX
+--------
+
+The IPX protocol has no tunable values in proc/sys/net.
+
+The IPX protocol does, however, provide proc/net/ipx. This lists each IPX
+socket giving the local and remote addresses in Novell format (that is
+network:node:port). In accordance with the strange Novell tradition,
+everything but the port is in hex. Not_Connected is displayed for sockets that
+are not tied to a specific remote address. The Tx and Rx queue sizes indicate
+the number of bytes pending for transmission and reception. The state
+indicates the state the socket is in and the uid is the owning uid of the
+socket.
+
+The /proc/net/ipx_interface file lists all IPX interfaces. For each interface
+it gives the network number, the node number, and indicates if the network is
+the primary network. It also indicates which device it is bound to (or
+Internal for internal networks) and the Frame Type if appropriate. Linux
+supports 802.3, 802.2, 802.2 SNAP and DIX (Blue Book) ethernet framing for
+IPX.
+
+The /proc/net/ipx_route table holds a list of IPX routes. For each route it
+gives the destination network, the router node (or Directly) and the network
+address of the router (or Connected) for internal networks.
+
+------------------------------------------------------------------------------
+Summary
+------------------------------------------------------------------------------
+Certain aspects of kernel behavior can be modified at runtime, without the
+need to recompile the kernel, or even to reboot the system. The files in the
+/proc/sys tree can not only be read, but also modified. You can use the echo
+command to write value into these files, thereby changing the default settings
+of the kernel.
+------------------------------------------------------------------------------
+
+
+
+
-The directory /proc/net/appletalk holds the list of active appletalk
-sockets on a machine.
-The fields indicate the DDP type, the local address (in network:node
-format) the remote address, the size of the transmit pending queue,
-the size of the received queue (bytes waiting for applications to
-read) the state and the uid owning the socket.
-
-/proc/net/atalk_iface lists all the interfaces configured for
-appletalk.It shows the name of the interface, its appletalk address,
-the network range on that ad- dress (or network number for phase 1
-networks), and the status of the interface.
-
-/proc/net/atalk_route lists each known network route. It lists the
-target (network) that the route leads to, the router (may be directly
-connected), the route flags, and the device the route is via.
-
-3.11 IPX
-
-The IPX protocol has no tunable values in /proc/sys/net.
-
-The IPX protocol does, however, provide /proc/net/ipx. This lists each
-IPX socket giving the local and remote addresses in Novell format
-(that is network:node:port). In accordance with the strange Novell
-tradition, everything but the port is in hex. Not_Connected is
-displayed for sockets that are not tied to a specific remote
-address. The Tx and Rx queue sizes indicate the number of bytes
-pending for transmit and receive. The state indicates the state the
-socket is in and the uid is the owning uid of the socket.
-
-The /proc/net/ipx_interface file lists all IPX interfaces. For each
-interface it gives the network number, the node number, and indicates
-if the network is the primary network. It also indicates which device it is bound to (or
-Internal for internal networks) and the Frame Type if
-appropriate. Linux supports 802.3, 802.2, 802.2 SNAP and DIX (Blue
-Book) ethernet framing for IPX.
-
-The /proc/net/ipx_route table holds a list of IPX routes. For each
-route it gives the destination network, the router node (or Directly)
-and the network address of the router (or Connected) for internal
-networks.
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)