Im experiencing write activity thats somewhat different from my previous qmail/courier-imap/Maildir setup. This more outspoken in v.1.1.x than v1.0.x (Im using Maildir).
Write activity is about half that of read activity when measuring throughput. But when measuring operations its about 5-7 times as high (measured with zpool iostat on ZFS).
I think this might be due to the many small updates to index and cache files. Anyway since writing is much more demanding to the disk than reads dovecots ends up being slower (only a little though) than my old qmail/courier-imap/Maildir was. And the old setup didnt even benefit from indexes like Dovecot does. (What I mean saying slower is that it can service fewer users before it hits the wall).
Of course theres also lots of benefits using Dovecot. Im just wondering whether this was a thing that should be focused on for later versions (maybe writes could be grouped together or something like that). Dovecot is very cheap on the CPU side so the only real limit in terms of scalability is the storage.
Regards, Mikkel