dovecot and glusterfs

[Michael Schwartzkopff]

Am Dienstag, 13. Januar 2015, 21:40:34 schrieb Nick Edwards:
> On 1/13/15, Michael Schwartzkopff <ms at sys4.de> wrote:
> > Hi,
> > 
> > I did some experiments with dovecot on a glusterfs on the active nodes
> > without
> > a director. So I had concurrent access to the files.
> > 
> > With the help of the available documentation about NFS and fcntl locks I
> > managed to find out the following:
> > 
> > With the plain mbox format dovecot seems to apply and to honor the fcntl
> > locks.  But since this format is not used any more in real setups, it is
> > useless.
> > 
> > With mdbox and maildir format I could reliably crash my mail storage just
> > by
> > 
> > delivering mails to the both dovecots via LMTP to the same user. In
> > maildir
> > 
> > dovecot seems not the set / respect the fnctl locks of the index file.
> > dotlocks
> > do not seems to work either with mdbox.
> > 
> > So I think the only solution os to use a director in a real world setup.
> > Or
> > is
> > there any non-obvious trick that I did not check?
> 
> Interesting, we use NFSv3 dovecot LDA with maildir, we have at present
> two dozen front end SMTP servers (using dovecot-lda) and some, hrmm we
> added a few more over Christmas, so I think about 32  pop3 servers,
> but with only 4 imap servers incl webmail (IMAP is not heavily used
> here due to government spy laws) talking to NAS storage server
> backend, *we do not use director* at all and has never been an issue.
> Director IIRC solves the problem of IMAP inconsistency, but we never
> see advantage when we tested, no doubt it solves some fancy setup
> problem, but since director can not help with pop3, it was not worth
> the hassle. never had any problems with webmail either, load balancers
> seem to look after it well

Yes. NFS has its own locking. I wanted to use plain glusterfs client without 
the detour of NFS. Thanks for your hint.

Mit freundlichen Grüßen,

Michael Schwartzkopff

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