Replication to more than one replica?

Per olof Ljungmark peo at intersonic.se
Fri Aug 10 10:52:39 EDT 2007


Rob Mueller wrote:
>> Could you do it then with sync_client -S -u instead of -r to one of 
>> the relicas?
> 
>       -u     User mode.  Remaining arguments are list of users who 
> should be replicated.
> 
> Which user though? You could do all users, but that takes time.
> 
> The point is that cyrus programs (lmtpd, imapd, etc) log actions that 
> change mailboxes, so you know exactly which mailboxes need syncing. It's 
> those logs you have to "play" twice to apply to two replicas to keep 
> replication as close as possible to real time.

It would be a way to keep a second offline replica for backing up to a 
tape archive, which is what I plan to do. I realize it's slower than the 
standard rolling replication but the archive is mainly for "ooops I 
deleted that mail" kind of scenario. In fact, I'm testing the setup 
right know with a list of all users. First run will take a while but 
further ones should only take a couple of minutes.

Of course this setup is a workaround and it gets increasingly more 
difficult with the number of users, here we only have around 500 
although many mailboxes are quite large.

Per olof


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