[Dovecot] 1.0rc8: another problem? Possibly 64-bit index?

[David Lee]

On Thu, 12 Oct 2006, John Peacock wrote:

> Timo Sirainen wrote:
> > Yep, this is a problem with dovecot.index.cache file created with 32bit
> > machine not working in 64bit machine. It should automatically detect
> > this and delete it, but for some reason it doesn't seem to work always.
> > You could do the exact same thing manually anyway by deleting them.
>
> Yes, but the OP was reporting trying to run *both* a 32-bit and a 64-bit
> server sharing the same NFS-mounted filesystem.  In other words, either
> you (Timo) need to change the indexes to be platform independent (i.e.
> no 64-bit-isms) or you need to put a BIG WARNING to not share the
> message indexes between different width platforms.  The performance hit
> of repeated nuking of the index files is going to be huge.

Indeed.  A fix, or a warning, would be very useful


> Obviously, the OP could also configure the index files to be located on
> a local filesystem (i.e. not shared in the message store), which should
> also be higher performance under all circumstances with networked
> message stores...

In such a set-up (set of front end IMAP/LDA machines, accessing shared
inbox/folder stores over NFS), what is the recommended place for the
indexes?  Shared (logically alongside the shared inbox/folder areas)?  Or
privately within each IMAP/LDA machine?

What are the locking implications on a busy mailstore?(*)  Although we try
to keep all activity for a given user on one machine, we cannot guarantee
this.  Suppose an email LDA/delivery occurs on one machine concurrently
with an IMAP update to the same folder from a different machine?  Or
similarly multiple simultaneous deliveries on different machines?  Etc.
What are the locking considerations for indexes then?


(*) We use trad. UNIX format.  Not ideal.  But we're not in a position to
migrate to (say) maildir.



-- 

:  David Lee                                I.T. Service          :
:  Senior Systems Programmer                Computer Centre       :
:                                           Durham University     :
:  http://www.dur.ac.uk/t.d.lee/            South Road            :
:                                           Durham DH1 3LE        :
:  Phone: +44 191 334 2752                  U.K.                  :