[Dovecot] Need to move mail

[Tom Allison]

Brent Clark wrote:
> Hi all
> 
> My imap server is getting to the stange where I need to start worring 
> about the disk usage.
> 
> Due to the number of users we seem to be hiring, I need to start looking 
> at a new mail server, suppose its a blessing in disguise too.
> 
> Would it be ok to just tar my current users mail (there home directory, 
> I dont use virtual setup) and the untar it on the new mail server.
> 
> Is there anything that dovecot on the new machine will complain about. 
> Obviously I would tar everything, indexes etc.
> 
> Just something I was wondering.
> 

I'm not an expert, but you could use tar or for that matter use rsync to 
do periodic updates from the old to the new with the final update being 
after hours when everyone is off the system.  rsync has options to 
preserve permissions and owners.  I think this would do nicely.

The advantage with rsync is that the first update would be huge and take 
many hours and really hog up the CPU/network/IO.  But you can rate limit 
rsync so it might run for a day but with a low enough performance that 
no one really notices.  After this, you can continue doing incremental 
backups with less data, higher data rates, for faster synchronizations. 
  Last day, you just knock everyone off the server and go full blast.

I would kill the indexes though.  They can be rebuilt and that way you 
know they are valid.  Might make the first day a bit ugly but if you 
were really bent on keeping the performance up, you could keep the 
indexes and hope they are 100% or write a script to Peek at everyones 
directories, forcing an index build.