[Dovecot] performance problems with {s,m}dbox

[Timo Sirainen]

On 31.7.2010, at 3.12, Jake Johnson wrote:

> using rc3 and with the latest pigeonhole, I had problems with dovecot
> (deliver) keeping up with high volumes of E-mail. I tried sdbox, mdbox, and
> cyrdir all with similar (failed) result.

What OS and filesystem?

> Jul 29 06:59:12 db1 dovecot: lda(XXXX): Error: Timeout while waiting for
> lock for transaction log file /home/XXXX/Maildir.mdbox/storage/dovecot.map
> .index.log

This happens only after the file has been locked for 3 minutes. Pretty much the only reason why that could happen is if there was another process rebuilding the mdbox storage because it was detected to be corrupted. There should be errors logged about it too..

> Jul 29 07:14:18 db1 dovecot: lda(XXXX): Panic: file dbox-file.c: line 76
> (dbox_file_free): assertion failed: (file->refcount == 0)

This is a bug in any case.. I'll see if I can figure out why it happened.

Did sdbox log about any errors? Or cydir? Especially cydir is a really really simple mailbox format and there is no reason why it could be slower than maildir or do any kind of a long locking.