increasing ulimit -n

[David]

On Fri, 2 Mar 2007, Alex Dean wrote:

> I've been reading about how it's possible to raise this limit by setting
> 'ulimit -n' to some higher number.  It's currently at 1024.  The only
> thing this machine does is MySQL, so there are no concerns about other
> users, etc.  Before I make any changes, though, I was hoping someone
> might help me figure out a reasonable way to increase this number. 
>This
> is new territory, so I'm wanting to tread cautiously.

generally you can set the limits on a per-user basis, which is better 
anyway.

Not sure about other distros, but for redhat, put the changes in 
/etc/security/limits.conf
i.e.:
mysqluser          soft    nproc           2047
mysqluser          hard    nproc           32768
mysqluser          soft    nofile          4096
mysqluser          hard    nofile          524288
mysqluser          hard    stack           65536
mysqluser          hard    memlock         3145728

Then, in the users .profile (or equivilant)
ulimit -u 32768 -n 524288 -l 3145728 -s 65536

One thing to be aware of, from the bash manpage:
A hard limit cannot be  increased  once it  is set; a soft limit may be 
increased up to the value of the hard limit.

This is what I use for my oracle servers, anyway.
David

-- 
"I find your lack of faith disturbing."
--Darth Vader
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