index.rst

  1===========================
  2Documentation for /proc/sys
  3===========================
  4
  5Copyright (c) 1998, 1999,  Rik van Riel <riel@nl.linux.org>
  6
  7------------------------------------------------------------------------------
  8
  9'Why', I hear you ask, 'would anyone even _want_ documentation
 10for them sysctl files? If anybody really needs it, it's all in
 11the source...'
 12
 13Well, this documentation is written because some people either
 14don't know they need to tweak something, or because they don't
 15have the time or knowledge to read the source code.
 16
 17Furthermore, the programmers who built sysctl have built it to
 18be actually used, not just for the fun of programming it :-)
 19
 20------------------------------------------------------------------------------
 21
 22Legal blurb:
 23
 24As usual, there are two main things to consider:
 25
 261. you get what you pay for
 272. it's free
 28
 29The consequences are that I won't guarantee the correctness of
 30this document, and if you come to me complaining about how you
 31screwed up your system because of wrong documentation, I won't
 32feel sorry for you. I might even laugh at you...
 33
 34But of course, if you _do_ manage to screw up your system using
 35only the sysctl options used in this file, I'd like to hear of
 36it. Not only to have a great laugh, but also to make sure that
 37you're the last RTFMing person to screw up.
 38
 39In short, e-mail your suggestions, corrections and / or horror
 40stories to: <riel@nl.linux.org>
 41
 42Rik van Riel.
 43
 44--------------------------------------------------------------
 45
 46Introduction
 47============
 48
 49Sysctl is a means of configuring certain aspects of the kernel
 50at run-time, and the /proc/sys/ directory is there so that you
 51don't even need special tools to do it!
 52In fact, there are only four things needed to use these config
 53facilities:
 54
 55- a running Linux system
 56- root access
 57- common sense (this is especially hard to come by these days)
 58- knowledge of what all those values mean
 59
 60As a quick 'ls /proc/sys' will show, the directory consists of
 61several (arch-dependent?) subdirs. Each subdir is mainly about
 62one part of the kernel, so you can do configuration on a piece
 63by piece basis, or just some 'thematic frobbing'.
 64
 65This documentation is about:
 66
 67=============== ===============================================================
 68abi/		execution domains & personalities
 69<$ARCH>		tuning controls for various CPU architecture (e.g. csky, s390)
 70crypto/		<undocumented>
 71debug/		<undocumented>
 72dev/		device specific information (e.g. dev/cdrom/info)
 73fs/		specific filesystems
 74		filehandle, inode, dentry and quota tuning
 75		binfmt_misc <Documentation/admin-guide/binfmt-misc.rst>
 76kernel/		global kernel info / tuning
 77		miscellaneous stuff
 78		some architecture-specific controls
 79		security (LSM) stuff
 80net/		networking stuff, for documentation look in:
 81		<Documentation/networking/>
 82proc/		<empty>
 83sunrpc/		SUN Remote Procedure Call (NFS)
 84user/		Per user namespace limits
 85vm/		memory management tuning
 86		buffer and cache management
 87xen/		<undocumented>
 88=============== ===============================================================
 89
 90These are the subdirs I have on my system or have been discovered by
 91searching through the source code. There might be more or other subdirs
 92in another setup. If you see another dir, I'd really like to hear about
 93it :-)
 94
 95.. toctree::
 96   :maxdepth: 1
 97
 98   abi
 99   fs
100   kernel
101   net
102   sunrpc
103   user
104   vm