very_dirty_syncs helped a lot - the problems still happen but only about every 30 minutes. It seems this flag prevents re-indexing on whatever was constantly inducing it (with every client-check, if there was a change written to the directory, is my best guess watching the logs go).
I still get all the same symptoms, but far less frequently.
I'm inclined to believe, as trivial as it may be to enumerate, that:
Something is triggering dovecot to believe the indexes need to be rebuilt.
When checking mail during the rebuild, clients get confused by UIDs in transition.
Today I had to quit TB and restart because duplicates filled my preview pane. Mulberry has been better, when it gets confused now, it is usually sufficient to initiate a manual check or expunge to get the list to update.
I would think that sdbox would alleviate these issues, no?
-------- Original Message -------- Subject: Re: Dovecot 2.2.16: disappearing messages, mismatched summaries, duplicated messages, excessive full re-downloads From: Timo Sirainen tss@iki.fi To: David Gessel gessel@blackrosetech.com Date: Sat Apr 18 2015 17:38:02 GMT+0300 (Arabic Standard Time)
On 18 Apr 2015, at 16:00, David Gessel gessel@blackrosetech.com wrote:
No. My best guess is that (your) ZFS+FreeBSD is simply not behaving the way Dovecot wants filesystems to behave (readdir() sometimes skipping over files). I don't have any other suggestion than trying a different filesystem or OS. I haven't heard ZFS having these problems before though.
Or migrating to sdbox. Absent any further suggestions, that will be my next step. My commitment to Maildir is far lower than my commitment to FreeBSD/ZFS. It is just a historical preference coming from a decade+ of courier IMAP.
Actually as a workaround you could try maildir_very_dirty_syncs=yes which gets rid of most of the readdir()s.