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