very slow syncing, any ideas?

[Michael Loftis]

--On October 19, 2006 8:10:13 PM +0200 Marten Lehmann <lehmann at cnm.de> 
wrote:

> 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).

Uhm... LA of 30 is very high.  What OS?  I assume Linux, vmstat 5 will tell 
you where you're hitting the wall, but unless you've got an 8 CPU machine 
LA 30 is rather quite high.  Linux LA is a measurement of processes blocked 
on I/O, processes running and processes waiting to run on a CPU.



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