| 1 | ===========================
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| 2 | Documentation for /proc/sys
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| 3 | ===========================
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| 4 |
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| 5 | Copyright (c) 1998, 1999, Rik van Riel <[email protected]>
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| 6 |
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| 7 | ------------------------------------------------------------------------------
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| 8 |
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| 9 | 'Why', I hear you ask, 'would anyone even _want_ documentation
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| 10 | for them sysctl files? If anybody really needs it, it's all in
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| 11 | the source...'
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| 12 |
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| 13 | Well, this documentation is written because some people either
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| 14 | don't know they need to tweak something, or because they don't
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| 15 | have the time or knowledge to read the source code.
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| 16 |
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| 17 | Furthermore, the programmers who built sysctl have built it to
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| 18 | be actually used, not just for the fun of programming it :-)
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| 19 |
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| 20 | ------------------------------------------------------------------------------
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| 21 |
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| 22 | Legal blurb:
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| 23 |
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| 24 | As usual, there are two main things to consider:
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| 25 |
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| 26 | 1. you get what you pay for
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| 27 | 2. it's free
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| 28 |
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| 29 | The consequences are that I won't guarantee the correctness of
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| 30 | this document, and if you come to me complaining about how you
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| 31 | screwed up your system because of wrong documentation, I won't
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| 32 | feel sorry for you. I might even laugh at you...
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| 33 |
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| 34 | But of course, if you _do_ manage to screw up your system using
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| 35 | only the sysctl options used in this file, I'd like to hear of
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| 36 | it. Not only to have a great laugh, but also to make sure that
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| 37 | you're the last RTFMing person to screw up.
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| 38 |
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| 39 | In short, e-mail your suggestions, corrections and / or horror
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| 40 | stories to: <[email protected]>
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| 41 |
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| 42 | Rik van Riel.
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| 43 |
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| 44 | --------------------------------------------------------------
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| 45 |
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| 46 | Introduction
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| 47 | ============
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| 48 |
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| 49 | Sysctl is a means of configuring certain aspects of the kernel
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| 50 | at run-time, and the /proc/sys/ directory is there so that you
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| 51 | don't even need special tools to do it!
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| 52 | In fact, there are only four things needed to use these config
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| 53 | facilities:
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| 54 |
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| 55 | - a running Linux system
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| 56 | - root access
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| 57 | - common sense (this is especially hard to come by these days)
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| 58 | - knowledge of what all those values mean
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| 59 |
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| 60 | As a quick 'ls /proc/sys' will show, the directory consists of
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| 61 | several (arch-dependent?) subdirs. Each subdir is mainly about
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| 62 | one part of the kernel, so you can do configuration on a piece
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| 63 | by piece basis, or just some 'thematic frobbing'.
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| 64 |
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| 65 | This documentation is about:
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| 66 |
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| 67 | =============== ===============================================================
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| 68 | abi/ execution domains & personalities
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| 69 | <$ARCH> tuning controls for various CPU architecture (e.g. csky, s390)
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| 70 | crypto/ cryptographic subsystem
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| 71 | debug/ debugging features
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| 72 | dev/ device specific information (e.g. dev/cdrom/info)
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| 73 | fs/ specific filesystems
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| 74 | filehandle, inode, dentry and quota tuning
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| 75 | binfmt_misc <Documentation/admin-guide/binfmt-misc.rst>
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| 76 | kernel/ global kernel info / tuning
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| 77 | miscellaneous stuff
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| 78 | some architecture-specific controls
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| 79 | security (LSM) stuff
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| 80 | net/ networking stuff, for documentation look in:
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| 81 | <Documentation/networking/>
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| 82 | proc/ <empty>
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| 83 | sunrpc/ SUN Remote Procedure Call (NFS)
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| 84 | user/ Per user namespace limits
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| 85 | vm/ memory management tuning
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| 86 | buffer and cache management
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| 87 | xen/ Xen hypervisor controls
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| 88 | =============== ===============================================================
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| 89 |
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| 90 | These are the subdirs I have on my system or have been discovered by
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| 91 | searching through the source code. There might be more or other subdirs
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| 92 | in another setup. If you see another dir, I'd really like to hear about
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| 93 | it :-)
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| 94 |
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| 95 | .. toctree::
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| 96 | :maxdepth: 1
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| 97 |
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| 98 | abi
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| 99 | crypto
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| 100 | debug
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| 101 | fs
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| 102 | kernel
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| 103 | net
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| 104 | sunrpc
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| 105 | user
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| 106 | vm
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| 107 | xen
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