file descriptors

Jules Agee julesa at
Tue Apr 29 13:28:20 EDT 2003

Hmm, I used to run out of file descriptors regularly on my Linux+Cyrus 
server until I put this in my /etc/rc.d/rc.local:

echo 65536 > /proc/sys/fs/file-max

According to /proc/sys/fs/file-nr, the system currently has 18150 files 
open, with 351 imapd processes running. This is pretty normal for this 

Hmmm, lsof shows about 50 open files for each imapd process... that's 
pretty close - 351*50=17550

But most of the "open files" lsof lists for an imapd process are shared 
libraries. Seems kind of brain dead to have the default system-wide 
file-max at 8192 if shared libraries get counted as open files once for 
each process running, but maybe I'm misinterpreting something.

Rob Siemborski wrote:
> There's really no reason Cyrus should be running out of file descriptors
> in normal operation (*maybe* mupdate can legitimately run out, under high
> load).
> What files are being held open by the processes that run out (lsof -p
> <pid>) ?
> -Rob
> On Tue, 29 Apr 2003, Michael Sims wrote:
>>There's probably a better way to do this, but I added "ulimit -n 8192" into
>>my startup script for cyrus, just before saslauthd and master are started...
>>Michael Sims
>>Project Analyst - Information Technology
>>Crye-Leike Realtors
>>Office: (901)758-5648  Pager: (901)769-3722
>>-----Original Message-----
>>From: owner-info-cyrus at
>>[mailto:owner-info-cyrus at]On Behalf Of Jon Rowell
>>Sent: Monday, April 28, 2003 1:48 PM
>>To: info-cyrus at
>>Subject: file descriptors
>>I am currently getting this error from master:
>>Apr 28 12:02:37 weathersby master[31748]: setrlimit: Unable to set file
>>ors limit to -1: Operation not permitted
>>Apr 28 12:02:37 weathersby master[31748]: retrying with 1024 (current
>>And then later I get an error about too many open files.  How can I up
>>the number of allowed open files?  I am running linux and cyrus 2.1.12.
>>Jon Rowell
> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
> Rob Siemborski * Andrew Systems Group * Cyert Hall 207 * 412-268-7456
> Research Systems Programmer * /usr/contributed Gatekeeper

Jules Agee
System Administrator
Pacific Coast Feather Co.
julesa at      x284

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