[CentOS] clustered mail server?

Mon May 19 12:38:21 UTC 2008
Les Mikesell <lesmikesell at gmail.com>

Christopher Chan wrote:
> 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?

That's generally my reasoning in thinking that simple raid1 mirrors on 
the primary with swappable disks and a spare powered-off chassis are 
probably more robust.  You do need someone on-site capable of swapping 
the disks if you have a motherboard/power supply failure but with 
server-class equipment and a good UPS those are pretty rare.  You also 
need additional backups, since an operator or software error could take 
out your online filesystem including the mirrored side.

   Les Mikesell
    lesmikesell at gmail.com