Beder at 01:35, 2 January 2013

Beder — Wed, 02 Jan 2013 01:35:09 GMT

← Older revision		Revision as of 01:35, 2 January 2013
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	= Solution =		= Solution =

	To increase the hard limits for users, you will need to create '''/~~sbin~~/initscript''' and place appropriate commands inside it. The easiest way is to copy the file '''/sbin/initscript.sample''' to '''/~~sbin~~/initscript''' and edit the copy, but you are certainly free to "roll your own." ~~If you decide to create your own, make sure it is executable or it will not work.~~		To increase the hard limits for users, you will need to create '''/etc/initscript''' and place appropriate commands inside it. The easiest way is to copy the file '''/sbin/initscript.sample''' to '''/etc/initscript''' and edit the copy, but you are certainly free to "roll your own."

	Using the following '''/~~sbin~~/initscript''' file:		Using the following '''/etc/initscript''' file:

	PATH=/bin:/sbin:/usr/bin:/usr/sbin		PATH=/bin:/sbin:/usr/bin:/usr/sbin
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	1024		1024

	Notice that the hardlimit is now 4096 (as specified in /~~sbin~~/initscript), but the softlimit is still 1024. In other words, you will still need to use /etc/profile (or some other shell init file - see below for recommendation) to raise the desired users' softlimits. With some creative scripting, you can be more selective about which users have what limits.		Notice that the hardlimit is now 4096 (as specified in /etc/initscript), but the softlimit is still 1024. In other words, you will still need to use /etc/profile (or some other shell init file - see below for recommendation) to raise the desired users' softlimits. With some creative scripting, you can be more selective about which users have what limits.

	Rather than editing the system /etc/profile, it's recommended to create a custom file in /etc/profile.d and make it executable. This way, you don't have to worry about trying to merge your changes to /etc/profile when doing Slackware upgrades to new versions.		Rather than editing the system /etc/profile, it's recommended to create a custom file in /etc/profile.d and make it executable. This way, you don't have to worry about trying to merge your changes to /etc/profile when doing Slackware upgrades to new versions.

Rworkman: Move from old wiki

Rworkman — Fri, 29 May 2009 00:17:30 GMT

Move from old wiki

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= Purpose =

This page does not attempt to explain the different types of system resource limits or when it is (or is not) appropriate to change them; see '''man ulimit''' and [[http://google.com Google]] for that discussion.

However, some users run into problems with the linux kernel's default limit settings, so we'll attempt to explain how to modify them to suit special needs.

= Overview =

The default settings provided by the kernel are sane values for most multi-user machines. Issuing the command '''ulimit -Hn''' should show the following:
user@host:~$ ulimit -Hn
1024
and '''ulimit -n''' should show this:
user@host:~$ ulimit -n
1024

The first command shows the hard limit set by the kernel, and the second command shows the soft limit set by the user. An unprivileged user can increase the soft limit (up to the hard limit value), and he is also able to lower the hard limit (but then is unable to increase it, as an unprivileged user cannot raise the hard limit at all).

There are some situations which might require a larger hard limit for users, and the obvious "solution" is to add a line in /etc/profile to increase it. However, this will not work, because normal users cannot increase their hard limits (as indicated above).

= Solution =

To increase the hard limits for users, you will need to create '''/sbin/initscript''' and place appropriate commands inside it. The easiest way is to copy the file '''/sbin/initscript.sample''' to '''/sbin/initscript''' and edit the copy, but you are certainly free to "roll your own." If you decide to create your own, make sure it is executable or it will not work.

Using the following '''/sbin/initscript''' file:

PATH=/bin:/sbin:/usr/bin:/usr/sbin
export PATH

# Increase the hardlimit for open files
ulimit -Hn 4096

# Execute the program.
eval exec "$4"

You should get the following after a reboot:
user@host:~$ ulimit -Hn
4096

user@host:~$ ulimit -n
1024

Notice that the hardlimit is now 4096 (as specified in /sbin/initscript), but the softlimit is still 1024. In other words, you will still need to use /etc/profile (or some other shell init file - see below for recommendation) to raise the desired users' softlimits. With some creative scripting, you can be more selective about which users have what limits.

Rather than editing the system /etc/profile, it's recommended to create a custom file in /etc/profile.d and make it executable. This way, you don't have to worry about trying to merge your changes to /etc/profile when doing Slackware upgrades to new versions.

= Other Resources =

* '''man initscript'''
* '''man ulimit'''

[[Category:Tutorials]]

Resource Limits - Revision history

Beder at 01:35, 2 January 2013

Rworkman: Move from old wiki