This documentation is for Dovecot v1.x, see wiki2 for v2.x documentation.

Server: Dell PowerEdge 1750, Dual Xeon 3GHz HT, 4GB RAM, 3x 74GB 15k SCSI, RAID level-5 PERC 4Di 128MB BBU.

Since 2010/2011 year we are on Dell PE 2850, Dual Xeon 2.66GHz HT (lower clock due less watts), 4GB RAM, 6x 74GB 15k SCSI, RAID level-5 ...

Antispam and webmail are another boxes.

Total mailboxs size: 100G (2009/08), we have quota :-)

Since 2010/2011 300G and using multi-instance (8x).

Software: Latest Dovecot (1.x), CentOS 5.x, Mysql 5.1 (5.0 before) user db on Myisam, Postfix 2.7 (postmulti used).

Users: 10,000, POP, IMAP, SquirrelMail, SMTP-AUTH.

Mailboxformat: maildir

We used Courier-IMAP before, works quite well, but Dovecot have lower load and is more friendly/configurable IMHO.

Every */5 hours rsync to hotswap server (HA via heartbeat).

Sar stat (2009/08):

                  CPU     %user     %nice   %system   %iowait    %steal     %idle
Average:          all      2.81      0.56      1.66      1.65      0.00     93.32

free -m:

             total       used       free     shared    buffers     cached
Mem:          3804       2903        900          0        357       1265
-/+ buffers/cache:       1280       2524
Swap:         4094          0       4094

Sar stat (2011/01):

                  CPU     %user     %nice   %system   %iowait    %steal     %idle
Average:          all      5.32      0.41      3.47      5.71      0.00     85.10

free -m:

             total       used       free     shared    buffers     cached
Mem:          4046       3723        323          0        289       2385
-/+ buffers/cache:       1048       2997
Swap:         4000         25       3974

Since 2010/11 we had problems with limits, currently runs ~400 imap and ~400 imap-login processes

IMAP: Warning: Inotify instance limit for user exceeded, disabling. Increase /proc/sys/fs/inotify/max_user_instances (set to 128)

Warning: All login processes are in use. You may need to increase login_max_processes_count (default 128)

Feel free to contact me at fuxa at unihost.cz if you have any questions.

None: DovecotServerInstallations/RHEL/10000 Users (last edited 2011-01-26 22:52:50 by ip-89-176-7-199)