dovecot - Oct 2010 - And again... too many open files

Hi!

Two days ago I upgraded to 1.2.15, and again I the warning

"Warning: fd limit 1024 is lower than what Dovecot can use under full
load"

reappeared.

It's a bit weird, because my actual limits are higher. From 
/etc/security/limits.conf

*               soft    nofile          4096
*               hard    nofile          8192
root            soft    nofile          4096
root            hard    nofile          8192
dovecot         soft    nofile          4096
dovecot         hard    nofile          8192

I added the * lines to avoid problems if a new user was involved, and finally 
supposed it was a bug in the detection process.

Today, as expected, dovecot was not responding with the famous "Too many
open
files" error. Has something changed? Is there some way to know which is the
maximum number of files that can be open? Is there some parameter I can change 
to avoid this?

Here's my dovecot -n

# 1.2.15: /usr/local/etc/dovecot.conf
# OS: Linux 2.6.18-164.11.1.el5 x86_64 Red Hat Enterprise Linux Server release 
5.4 (Tikanga) 
syslog_facility: local1
protocols: imap imaps pop3 pop3s
listen(default): *:143
listen(imap): *:143
listen(pop3): *:110
ssl_listen(default): *:993
ssl_listen(imap): *:993
ssl_listen(pop3): *:995
ssl_cert_file: /usr/share/ssl/certs/imapd.pem
ssl_key_file: /usr/share/ssl/certs/imapd.pem
disable_plaintext_auth: no
login_dir: /usr/local/var/run/dovecot/login
login_executable(default): /usr/local/libexec/dovecot/imap-login
login_executable(imap): /usr/local/libexec/dovecot/imap-login
login_executable(pop3): /usr/local/libexec/dovecot/pop3-login
login_process_per_connection: no
login_process_size: 256
login_processes_count: 16
login_max_processes_count: 256
login_max_connections: 512
max_mail_processes: 2048
first_valid_uid: 100
mail_location: maildir:~/Maildir:INDEX=/var/dovecot/%u:CONTROL=/var/dovecot 
nas/%u/control
mail_nfs_storage: yes
lock_method: dotlock
mail_executable(default): /usr/local/libexec/dovecot/imap
mail_executable(imap): /usr/local/libexec/dovecot/imap
mail_executable(pop3): /usr/local/libexec/dovecot/pop3
mail_plugins(default): quota imap_quota
mail_plugins(imap): quota imap_quota
mail_plugins(pop3): quota
mail_plugin_dir(default): /usr/local/lib/dovecot/imap
mail_plugin_dir(imap): /usr/local/lib/dovecot/imap
mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3
pop3_uidl_format(default): %08Xu%08Xv
pop3_uidl_format(imap): %08Xu%08Xv
pop3_uidl_format(pop3): %v.%u
auth default:
  cache_size: 1000
  cache_ttl: 6000
  master_user_separator: *
  debug: yes
  passdb:
    driver: passwd-file
    args: /usr/local/etc/bloqueados
    deny: yes
  passdb:
    driver: ldap
    args: /usr/local/etc/dovecot-ldap.conf
  passdb:
    driver: passwd-file
    args: /usr/local/etc/shadow
  passdb:
    driver: pam
  passdb:
    driver: passwd-file
    args: /usr/local/etc/dovecot-master.conf
    master: yes
  userdb:
    driver: prefetch
  userdb:
    driver: passwd-file
    args: /usr/local/etc/passwd
  userdb:
    driver: ldap
    args: /usr/local/etc/dovecot-ldap.conf
  socket:
    type: listen
    master:
      path: /var/run/dovecot/auth-master
      mode: 384
plugin:
  quota: fs
-- 
Joseba Torre. Vicegerencia de TICs, ?rea de Explotaci?n

On Wed, 2010-10-06 at 10:34 +0200, Joseba Torre wrote:
> "Warning: fd limit 1024 is lower than what Dovecot can use under full
load"
> 
> reappeared.
> 
> It's a bit weird, because my actual limits are higher. From 
> /etc/security/limits.conf
These limits don't affect Dovecot at all, because they're for users that
are actually logging in (via PAM). System services get their limits
elsewhere.
> # OS: Linux 2.6.18-164.11.1.el5 x86_64 Red Hat Enterprise Linux Server
> release 
I don't really know what the correct place to put it would be in RHEL.
One way at least that might work (I'm not sure) would be to put

ulimit -n 4096

to /etc/sysconfig/dovecot