file descriptors

Rob Siemborski rjs3 at
Tue Apr 29 13:33:07 EDT 2003

On Tue, 29 Apr 2003, Jules Agee wrote:

> 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

Right, I was thinking of per-process file descriptors.

> 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
> server.
> 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.

Yes, that's very low, especially for the number of shared libraries that
a program like cyrus makes use of.

You might be able to cut this down somewhat if you remove unneeded SASL
plugins from /usr/lib/sasl and /usr/lib/sasl2 (or compile in a static
SASL library).


Rob Siemborski * Andrew Systems Group * Cyert Hall 207 * 412-268-7456
Research Systems Programmer * /usr/contributed Gatekeeper

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