Re: ulimit -n vs client_limit vs process_limit

On Thu, 17 Dec 2020, Aki Tuomi wrote:

...

What should I set "ulimit -n" relative to client_limit? Or perhaps I've roofed

You need to adjust LimitNOFiles (or ulimit -n). Dovecot needs more file descriptors than just the ones used by imap-login process, so it is a good idea to consider setting it to at least 3x time the value.

Thanks, good to know.

Out of curiosity, I did a snapshot of FD usage for dovecot's supervisory processes:

# for p in imap-login config log auth pop3-login stats dovecot anvil; do
#	echo "$p \c"; ls /proc/`pgrep -f /$p`/fd | wc -l
# done

imap-login     357
config      14
log      38
auth      22
pop3-login      20
stats     193
dovecot     221
anvil      18

I guess "dovecot" or "stat" are the particular processes that needs to have FD limits set larger than to the sum of client_limits.

Joseph Tam <jtam.home@gmail.com>