migration from 2.1.x to 2.4.5

[Andrew Morgan]

On Wed, 1 Dec 2010, Ron Vachiyer wrote:

>
> Hello,
>
> I am pretty much done testing a 2.4.5 Cyrus setup to replace an aging 
> (2.1.x) installation.  I have about 36GB of spool, 11,000 accounts or 
> so.
>
> I have done some small-scale testing of using imapsync to fetch the 
> contents of the legacy imap folders which seem to work successfully. 
> My question is, when it comes time to migrate, is it safe to allow lmtpd 
> to forward mails to mailboxes that theoretically could be getting 
> imapsync'ed at that time?  Or is my only option to spool inbound emails 
> until the imapsync is done?  I'm guessing that, from the speed I saw 
> imapsync run, that this might take a good number of hours to complete. 
> As well, is it safe/unsafe to allow imap/pop3 connections to those same 
> mailboxes during the sync?
>
> I am open to any ideas should I be looking at this migration the wrong 
> way.  I read about using rsync to copy the files directly, however I am 
> wondering if the jump between 2.1 and 2.4 might be too large and cause 
> unforseen issues.

Why not run imapsync multiple times in the lead-up to the actual 
migration?  That way, your final migration can be very short because there 
will be very little data that needs to be sync'd.  I think it would be 
wise to disable imap/pop3 connections and lmtp delivery while you are 
performing the final migration.

 	Andy