4096 file descriptors

[ktm at rice.edu]

On Wed, Aug 22, 2012 at 02:43:09PM -0400, Ron Vachiyer wrote:
> Quick question about filedescriptors.  On Centos6, cyrus 2.3.16 seems to be able to open 4096 FDs ;
> 
> master[27121]: retrying with 4096 (current max)
> 
> ulimit -a says 1024;
> 
> open files                      (-n) 1024
> 
> I am looking to increase this, and have found some documentation saying to increse file-max in /proc.  However, file-max already has a much larger number;
> 
> cat /proc/sys/fs/file-max
> 1201105
> 
> The only way I have found so far is to add a ulimit -n 8192 in /etc/rc.d/init.d/cyrus-imapd
> 
> 
> Is there a more generic/cleaner way to do this?
> 
> Thanks,
> 
> Ron
> 
> 
Hi Ron,

I do not know if this is applicable to Centos6, but Redhat 6 shipped with this
file: 

/etc/security/limits.d/90-nproc.conf 
# Default limit for number of user's processes to prevent
# accidental fork bombs.
# See rhbz #432903 for reasoning.

*          soft    nproc     65535

except the limit was 1024. Argh! We bumped it here and we were good. Note,
do NOT remove the file or a patch/update will re-create it with the expected
negative consequences for a busy system.

Regards,
Ken