[Dovecot] imap-login processes

[Bryan Polk]

First, thanks for this great product. We migrated from Courier last week 
with only small bumps along the way. We have a few hundred active users 
with a mix of pop3 and imap clients. The server is running on sparc 
Solaris 9.

We're seeing a problem now with the number of "imap-login" processes 
rising slowly to it's limit and then (understandably) not letting any more 
logins happen. Legitimate users seem to have no problem logging in until 
the limit is hit. Another odd thing is that this is not a problem for 
pop3-login processes, just imap...

I've tried changing some obvious things including the passdb from pam to 
passwd and back again, but here's the current dovecot -n output:


# 1.0.13: /opt/dovecot/etc/dovecot.conf
protocols: imap imaps pop3 pop3s
ssl_cert_file: /opt/dovecot/etc/ssl/certs/dovecot.pem
ssl_key_file: /opt/dovecot/etc/ssl/certs/key.pem
disable_plaintext_auth: no
login_dir: /opt/dovecot/var/run/dovecot/login
login_executable(default): /opt/dovecot/libexec/dovecot/imap-login
login_executable(imap): /opt/dovecot/libexec/dovecot/imap-login
login_executable(pop3): /opt/dovecot/libexec/dovecot/pop3-login
login_processes_count: 12
login_max_processes_count: 512
verbose_proctitle: yes
mail_location: maildir:~/Maildir
mmap_disable: yes
mail_executable(default): /opt/dovecot/libexec/dovecot/imap
mail_executable(imap): /opt/dovecot/libexec/dovecot/imap
mail_executable(pop3): /opt/dovecot/libexec/dovecot/pop3
mail_plugin_dir(default): /opt/dovecot/lib/dovecot/imap
mail_plugin_dir(imap): /opt/dovecot/lib/dovecot/imap
mail_plugin_dir(pop3): /opt/dovecot/lib/dovecot/pop3
pop3_uidl_format(default):
pop3_uidl_format(imap):
pop3_uidl_format(pop3): %08Xu%08Xv
namespace:
   type: private
   prefix: INBOX.
   inbox: yes
auth default:
   verbose: yes
   passdb:
     driver: pam
   userdb:
     driver: passwd



Any ideas or advice?

Thanks,


Bryan Polk
Unix Systems Administrator
Communication and Multimedia Services
FAMU-FSU College of Engineering
bpolk at eng.fsu.edu