[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