At work, we're going to start offering webhosting for our local area and customers. It's been my contention since day one that we need to offer high availability service...if a box dies, it needs to rollover to another box asap, so customers see zero downtime.

Well, everyone agreed, and someone suggested that we cluster the computers. However, clustering in the sense that I know it is WAY too much to do.

Basically, we have 2 machines (2x2.8ghz,6gb,3x73gb) machines running Redhat. The hosting software is to be CPanel.

We need machine1 to be constantly and 100% accurately mirrored on machine2.
Is this clustering? If so, what flavor is it? To me, this would seem to be an LVS, but I honestly don't know if this is the right solution or not.

What I am proposing is to use RSYNC and simply roll the box over when the other goes down. Even then, I'm not sure f this is the right approach.

Any thoughts on this? Any recommendations on layout/design or even preferred software?
I'm the software guy, and this type of stuff just baffles me, so any thoughts would be appreciated.

Greetings:

Clustering generally means two or more computers that are bound together to act as one.

Load balancing generally means two or more computers that share the work load.

Mirroring generally means two or more that have the same content.

Thank you.

One of the best resources about Linux clustering is http://lcic.org - you probably want to go throught it.

There are many forms of clustering (Load Balanced, High Availability/Failover, Cluster File Server, Cluster Database Server, and SSI [Single System Image]) and they are all different. What you are trying to achieve is the High Availability/Failover type of cluster.

For that, you probably want to get an external storage controller (something like http://www.dynamicnetworkfactory.com/RAID/DataMax14000RAID.htm [not a recommendation, just the first one that popped up on a quick Google search]). It has the advantage of having two SCSI inputs (which means you can connect both servers connected to it). Then, using any of the HA software packages mentioned at lcic.org, should the first box fail - the second could mount its disk drives and serve the web pages.