Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | Documentation for /proc/sys/ kernel version 2.2.10 |
| 2 | (c) 1998, 1999, Rik van Riel <riel@nl.linux.org> |
| 3 | |
| 4 | 'Why', I hear you ask, 'would anyone even _want_ documentation |
| 5 | for them sysctl files? If anybody really needs it, it's all in |
| 6 | the source...' |
| 7 | |
| 8 | Well, this documentation is written because some people either |
| 9 | don't know they need to tweak something, or because they don't |
| 10 | have the time or knowledge to read the source code. |
| 11 | |
| 12 | Furthermore, the programmers who built sysctl have built it to |
| 13 | be actually used, not just for the fun of programming it :-) |
| 14 | |
| 15 | ============================================================== |
| 16 | |
| 17 | Legal blurb: |
| 18 | |
| 19 | As usual, there are two main things to consider: |
| 20 | 1. you get what you pay for |
| 21 | 2. it's free |
| 22 | |
| 23 | The consequences are that I won't guarantee the correctness of |
| 24 | this document, and if you come to me complaining about how you |
| 25 | screwed up your system because of wrong documentation, I won't |
| 26 | feel sorry for you. I might even laugh at you... |
| 27 | |
| 28 | But of course, if you _do_ manage to screw up your system using |
| 29 | only the sysctl options used in this file, I'd like to hear of |
| 30 | it. Not only to have a great laugh, but also to make sure that |
| 31 | you're the last RTFMing person to screw up. |
| 32 | |
| 33 | In short, e-mail your suggestions, corrections and / or horror |
| 34 | stories to: <riel@nl.linux.org> |
| 35 | |
| 36 | Rik van Riel. |
| 37 | |
| 38 | ============================================================== |
| 39 | |
| 40 | Introduction: |
| 41 | |
| 42 | Sysctl is a means of configuring certain aspects of the kernel |
| 43 | at run-time, and the /proc/sys/ directory is there so that you |
| 44 | don't even need special tools to do it! |
| 45 | In fact, there are only four things needed to use these config |
| 46 | facilities: |
| 47 | - a running Linux system |
| 48 | - root access |
| 49 | - common sense (this is especially hard to come by these days) |
| 50 | - knowledge of what all those values mean |
| 51 | |
| 52 | As a quick 'ls /proc/sys' will show, the directory consists of |
| 53 | several (arch-dependent?) subdirs. Each subdir is mainly about |
| 54 | one part of the kernel, so you can do configuration on a piece |
| 55 | by piece basis, or just some 'thematic frobbing'. |
| 56 | |
| 57 | The subdirs are about: |
| 58 | abi/ execution domains & personalities |
| 59 | debug/ <empty> |
| 60 | dev/ device specific information (eg dev/cdrom/info) |
| 61 | fs/ specific filesystems |
| 62 | filehandle, inode, dentry and quota tuning |
| 63 | binfmt_misc <Documentation/binfmt_misc.txt> |
| 64 | kernel/ global kernel info / tuning |
| 65 | miscellaneous stuff |
| 66 | net/ networking stuff, for documentation look in: |
| 67 | <Documentation/networking/> |
| 68 | proc/ <empty> |
| 69 | sunrpc/ SUN Remote Procedure Call (NFS) |
| 70 | vm/ memory management tuning |
| 71 | buffer and cache management |
| 72 | |
| 73 | These are the subdirs I have on my system. There might be more |
| 74 | or other subdirs in another setup. If you see another dir, I'd |
| 75 | really like to hear about it :-) |