[CentOS] clustered mail server?

Mon May 19 09:41:10 UTC 2008
Christopher Chan <christopher at ias.com.hk>

Christopher Chan wrote:
> Ralph Angenendt wrote:
>> Christopher Chan wrote:
>>> Okay, Les helped me with that one. RAID1 on the network. So you would 
>>> have to use GFS or something like that with it and have the service 
>>> down on the secondary unless it was sendmail you were running.
>> No and yes. You can just use ext3 on both nodes as you normally only
>> have the one on the primary node mounted - the other one is not accessed
>> by anything. And yes, with heartbeat you "just" failover to the second
>> node, if the first one is dead. That will start the needed services on
>> the second node.
> Are you positive that you can put ext3 on it and have it mounted on the 
> secondary while the primary is happily hammering away without any ill 
> effects? Have you done it?

Sorry, I did not read your mail through properly. Not mounted on the 
secondary, okay. Anyway, quite a fair bit off complexity there in making 
sure the network block device does not get mounted by both boxes at the 
same time.

Is it really worth the complexity when you can have both servers online 
running off their own disks for the mail queue without having to worry 
about the other guy? If the primary is so badly whatever that a queue on 
mirrored disks cannot be brought back online with a simple reboot, what 
chances are there that the network block device won't be a victim of the 
whatever and mess up the queue so that the secondary cannot use it?