Dovecot performance tuning
==========================

Disk I/O optimization
---------------------

Usually heavily loaded IMAP and POP3 servers don't use much CPU, but they use
all the disk I/O they can get. So reducing disk I/O is probably the most useful
optimization you can do.

 * See <MailLocation.LocalDisk.txt> for generic disk I/O optimizations.
 * See <MailLocation.Mbox.txt> for mbox-specific optimizations.
 * See <MailLocation.Maildir.txt> for Maildir-specific optimizations.

CPU usage optimization
----------------------

 * See <LoginProcess.txt> for optimizing CPU usage caused by logins
 * See 'auth_cache_size' setting for caching passdb and userdb lookups

Memory usage optimization
-------------------------

There aren't many settings which affect Dovecot's memory usage. About the only
such settings are 'auth_cache_size' and <LoginProcess.txt> settings. In general
Dovecot uses as much memory as it needs, which is usually quite little.

Note that these settings do not directly affect the memory usage:

 * 'login/mail/auth_process_size': These are simply safe guards against
   potential memory leaks. If the process's virtual size reaches the limit, the
   process is killed by the kernel.
 * 'login_max_processes_count', 'max_mail_processes' and
   'auth_worker_max_count': These are mostly to avoid DoS attacks using up all
   your memory.

(This file was created from the wiki on 2009-01-05 04:42)
