Cyrus 2.3.7 Replication Question

Scott Russell lnxgeek at
Wed Jul 12 20:33:16 EDT 2006

Robert Mueller wrote:
>> 1) Server A dies
>> 2) Users are sent to Server B via DNS redirects
>> 3) Server A is restored
>> 4) Mailboxes on Server B are now more 'current' than mailboxes on 
>> Server A
>> In other words, the failover is easy(ish) but the failback has me 
>> scratching my head. I Think two way replication solves that.
> Once you've got Server A back, you have to make sure that when you 
> start it you've disabled the sync_client and all IMAP/POP/LMTP 
> connections to Server A, otherwise if you have things happening to 
> both of them at the same time, you'll be in big trouble since there 
> won't be an "authorative" server anymore.
> Before you change back to the original setup, you have to change the 
> configuration so that Server B has a sync_client and Server A has a 
> sync_server, and run replication back the other way until all the 
> mailboxes on Server A are back up to date with the contents of Server 
> B (and probably for safety do a sync_client -u on each user), then 
> switch over back to the original setup.

Interesting. This process also implies you want to stop incoming mail 
for a period of time to both servers. Sound right?

Scott Russell <lnxgeek at>
IBM Linux Technology Center, System Admin

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