[CentOS] Webserver redundancy - help

Thu Mar 23 14:21:38 UTC 2006
Steve Huff <shuff at vecna.org>

On Mar 23, 2006, at 8:57 AM, Wayne wrote:

> My problem is there is no redundancy. If webserver 1 goes down then  
> clients
> A,B,C have no services.
> I need to add in redundancy. I can't at the moment afford a 4th  
> server.
> So I need to make do with whats currently there.

you might want to think about run a Red Hat Cluster Suite cluster,  
since it's been ported to CentOS.  read the readme here:

http://mirror.centos.org/centos/4/csgfs/Readme.txt

be aware that while i believe that this system would satisfy your  
needs (based on the information you've provided), setting up CS/GFS  
is a nontrivial task.  read all the docs and be sure you understand  
what you're doing; if not, ask.

important considerations:
1) you *need* shared storage.  use a fibre channel or iSCSI SAN, or  
use an external disk chassis with a scsi controller for each host.
2) you *need* some automatic means of fencing (i.e. power-cycling)  
the hosts in the cluster.  a network-controlled power switch will do  
this well; if you don't want to buy one, some servers have remote  
management ports that will permit fencing.

-steve


---
If this were played upon a stage now, I could condemn it as an  
improbable fiction. - Fabian, Twelfth Night, III,v