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0001 Documentation for /proc/sys/            kernel version 2.2.10
0002         (c) 1998, 1999,  Rik van Riel <>
0004 'Why', I hear you ask, 'would anyone even _want_ documentation
0005 for them sysctl files? If anybody really needs it, it's all in
0006 the source...'
0008 Well, this documentation is written because some people either
0009 don't know they need to tweak something, or because they don't
0010 have the time or knowledge to read the source code.
0012 Furthermore, the programmers who built sysctl have built it to
0013 be actually used, not just for the fun of programming it :-)
0015 ==============================================================
0017 Legal blurb:
0019 As usual, there are two main things to consider:
0020 1. you get what you pay for
0021 2. it's free
0023 The consequences are that I won't guarantee the correctness of
0024 this document, and if you come to me complaining about how you
0025 screwed up your system because of wrong documentation, I won't
0026 feel sorry for you. I might even laugh at you...
0028 But of course, if you _do_ manage to screw up your system using
0029 only the sysctl options used in this file, I'd like to hear of
0030 it. Not only to have a great laugh, but also to make sure that
0031 you're the last RTFMing person to screw up.
0033 In short, e-mail your suggestions, corrections and / or horror
0034 stories to: <>
0036 Rik van Riel.
0038 ==============================================================
0040 Introduction:
0042 Sysctl is a means of configuring certain aspects of the kernel
0043 at run-time, and the /proc/sys/ directory is there so that you
0044 don't even need special tools to do it!
0045 In fact, there are only four things needed to use these config
0046 facilities:
0047 - a running Linux system
0048 - root access
0049 - common sense (this is especially hard to come by these days)
0050 - knowledge of what all those values mean
0052 As a quick 'ls /proc/sys' will show, the directory consists of
0053 several (arch-dependent?) subdirs. Each subdir is mainly about
0054 one part of the kernel, so you can do configuration on a piece
0055 by piece basis, or just some 'thematic frobbing'.
0057 The subdirs are about:
0058 abi/            execution domains & personalities
0059 debug/          <empty>
0060 dev/            device specific information (eg dev/cdrom/info)
0061 fs/             specific filesystems
0062                 filehandle, inode, dentry and quota tuning
0063                 binfmt_misc <Documentation/binfmt_misc.txt>
0064 kernel/         global kernel info / tuning
0065                 miscellaneous stuff
0066 net/            networking stuff, for documentation look in:
0067                 <Documentation/networking/>
0068 proc/           <empty>
0069 sunrpc/         SUN Remote Procedure Call (NFS)
0070 vm/             memory management tuning
0071                 buffer and cache management
0072 user/           Per user per user namespace limits
0074 These are the subdirs I have on my system. There might be more
0075 or other subdirs in another setup. If you see another dir, I'd
0076 really like to hear about it :-)