ZFS: data sometimes not getting correctly flushed to disk (possible mmap/write issue)?

[Brian Biskeborn]

This has been happening to me for a week or so (same setup - Dovecot on 
ZFS). I'll disable mmap and see whether it persists.

Brian

Peter Schuller wrote:
>> 3) ktracing gen2.py shows that the py-mutagen library seems to do both
>> write()s and read/write mmap()s to the file to update the file.
> 
> FWIW, ever since a dovecot installation of mine was moved onto ZFS one gets 
> sporadic 'internel errors' from dovecot. Dovecot logs that index files are 
> corrupt, and marked broken. Recovery involves re-selecting the IMAP mailbox.
> 
> In response to your post, I recently turned OFF use of mmap in dovecot 
> (mmap_disable = yes), and the problem seems to have gone away immediately.
> 
> If it should show up again in spite of mmap being disabled I will post a 
> follow-up, but it's been long enough that I believe the problem to be gone.
>