[Dovecot] Adding capacity by simply migrating to dovecot -- thank you
We run a mail service with some hundreds of domains and thousands of users. Xeon 2 CPU server hosting the imap, pop, webmail, db and all trimmings (sepparate servers scanning for spam/viri) The server was io saturated and performing poorly, especially for large webmail users. A constant queue of hundreds of ops per second were taking too many miliseconds each (gstat.) Load average often spiked over 15! We planned to add a second backend imap/pop machine but first migrated to dovecot (from courier.) Like a miracle, the load average stays below 1 now, nor do the disks saturate! All's well and webmail performs snappily even during peak usage! Granted we also upgraded freebsd which supposedly has made leaps to better schedule tasks across multiple processors, but this is not a many core machine - just 2. We almost don't need to scale up our architecture, tho will, thanks so very much for this wonderful software Timo!
Re: [Dovecot] Adding capacity by simply migrating to dovecot -- thank you
On Wed, 2009-12-09 at 12:43 -0800, Benjamin Connelly wrote: Like a miracle, the load average stays below 1 now, nor do the disks saturate! All's well and webmail performs snappily even during peak usage! If you still want to reduce disk IO, you can also try (if you haven't already): - deliver: http://wiki.dovecot.org/LDA/Indexing - maildir_very_dirty_syncs=yes: http://wiki.dovecot.org/MailLocation/Maildir signature.asc Description: This is a digitally signed message part
Re: [Dovecot] Adding capacity by simply migrating to dovecot -- thank you
If you still want to reduce disk IO, you can also try (if you haven't already): - deliver: http://wiki.dovecot.org/LDA/Indexing - maildir_very_dirty_syncs=yes: http://wiki.dovecot.org/MailLocation/Maildir We did switch from maildrop (and courier authd and cyrus sasl) to just dovecot (+sieve +manage sieve, a great simplification to build and maintain) and will ponder very dirty syncs. . .
