On 17.2.2013, at 0.12, Michael Grimm trashcan@odo.in-berlin.de wrote:
I might add that both servers run inside FreeBSD jails (if that might make the difference to your test setup.
Inside jail Dovecot sees two different hostnames (same as "hostname" command)?
Hmm. Both jails run at distinct servers. ssh replication uses different domains, though. But, both jails are named identically "test", and both jails resolve to identical hostnames "test" if using "hostname". But, a "hostname -f" is lacking to return "test.mx1.invalid" and "test.mx2.invalid", respectively (although a "nslookup test" does). Hmm, do you think I should need to provide different hostnames in both jails?
That's the problem most likely. I'd guess Dovecot sees both servers as having "test" as the hostname and each server thinks it's the one that should be doing the locking and not the other.
See if this helps: http://hg.dovecot.org/dovecot-2.2/rev/e7aabd79c9d5