[Dovecot] Best way to migrate versions and machines

[Donny Brooks]

On 2/21/2011 9:46 AM, Rick Romero wrote:
>
> Quoting Ed W <lists at wildgooses.com>:
>
>> On 17/02/2011 15:29, Donny Brooks wrote:
>>> We are looking to migrate from our current mail server running 
>>> dovecot-1.2.11-3 to a new mail server running the latest dovecot 
>>> (2.0.9?). So this would not only be a version change but also a 
>>> machine change. We currently use Maildir for storing mail and would 
>>> like to stay that way.
>>>
>>> Has anyone preformed such a feat and it worked? Looking for any input.
>>>
>>
>
> I've done it two ways - Rsync and ZFS snapshots.  Both methods are 
> pretty much the same.
> I have multiple satellites doing SMTP incoming/outgoing and dovecot on 
> a primary 'file server' with NFS exports.
> 1. replicate all data
> 2. replicate diff data  (do this until the update window is small)
> 3. disable deliveries (for me, disable qmail-send, umount NFS mounts)
> 4. replicate diff data
> 5. turn off IMAP/POP
> 6. replicate diff data
> 7. Migrate IP address/Change FW rules/etc
> 8. Turn on IMAP/POP
> 9. Turn on deliveries
>
> For my last ZFS migration I only had 2 minutes of 'downtime' from the 
> user's perspective (Step 5 -> Step 8), as the necessary changes were 
> already staged.
>
> Rick
>
>
>
Sounds similar to what I was thinking. I was just not sure if there was 
some unforeseen gotchas that others had dealt with before. The move to a 
new version is usually not that bad but I knew moving machines with 
versions could be hazardous. I may end up upgrading the local copy to 
2.0.9 before the move so they will be similar.