very slow syncing, any ideas?

[Michael Menge]

Hi,

i had much better performance with mailutil from UW-Imapd. It uses the  
IMAP-protocol like imapscyn but is not a scipt but a binary program  
and uses the imap APPEND command and does noe checks to see wich  
E-Mails are on the new server.

Michael Menge

Quoting Marten Lehmann <lehmann at cnm.de>:

> Hello,
>
> I'm about to migrate several thousand mailboxes from Maildir to Cyrus
> using the tool imapsync. It does its job very well and when I tested
> the migration on a small development server it was very fast.
>
> But now on the production system the synchronisation is very slow with
> a maximum of one message per second (and we have gigabytes of messages
> in the storage, partically > 10,000 messages per mailbox!). The general
> load of the system isn't very high, maybe a load average of 30. I
> disabled the duplicate message suppression. The mailboxes.db is about 8
> megabytes big with approx. 13,000 mailboxes and 4 default folders each
> (Drafts, Junk, Sent, Trash).
>
> I have the following entries in my configuration which should provide a
> better hierarchie and balance of directories than if they were all in
> one main directory:
>
> altnamespace: true
> hashimapspool: true
> unixhierarchysep: true
> virtdomains: userid
>
> I also tried to move the old Maildirs to a different server, so that
> getting messages from the old mailbox and putting it to the new mailbox
> through IMAP doesn't come up with reads and writes on the same server.
> But the performance benefit was minimal.
>
> But in the end, syncing is still really slow. It would take weeks to
> sync all mailboxes that way.
>
> How else could we move them to the new storage if doing it through IMAP
> is too slow? On the other hand we would like to keep all flags so I
> guess syncing it with IMAP is the only choice?
>
> What could be the reason to be that slow? Is it the big mailboxes.db?
>
> Regards
> Marten
> ----
> Cyrus Home Page: http://cyrusimap.web.cmu.edu/
> Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki
> List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html



--------------------------------------------------------------------------------
M.Menge                                 Tel.: (49) 7071/29-70316
Universitaet Tuebingen                  Fax.: (49) 7071/29-5912
Zentrum fuer Datenverarbeitung          mail:  
michael.menge at zdv.uni-tuebingen.de
Waechterstrasse 76
72074 Tuebingen
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 5469 bytes
Desc: S/MIME krytographische Unterschrift
Url : http://lists.andrew.cmu.edu/pipermail/info-cyrus/attachments/20061020/da0ea977/smime.bin