[ILUG] Backups and clustering.

[Darragh]

Good morning, 

I'm running a number of small virtual Linux servers at the moment.

The set up is as follows: 
One ESX 4 server. Plenty of RAM and two quad core processors. 
I have three data stores on the virtual machine. 
1 virtual disk for the OS. This is almost full. There is currently not enough space to do a snap shot. This is two SAS drives in RAID 1. 
1 2TB virtual disk for backups. This is all but empty. It has two SATA drives in RAID 1. 
Finally, I have 1 virtual disk with 4 450GB SAS drives. This is used as one single file store. 

Everything is running well on it but I'm concerned about the lack of redundancy. 

Because I cannot create a snapshot of any of the Linux VM's I'm not sure what the best way is to back up these machines.  I was hoping to have something running that would simply dump the snapshots onto another disk but I'm not sure how possible this is considering there's not enough space on the data store where the operating systems are installed. 

I'd also like to have some kind of off site failover so that if the main machine went down the important VM's could still be available somewhere else. I have somewhere in mind for this so my other question is, Is there a way of having a scheduled sincronization of the apache config? I'm trying not to over complicate this so would I be right in saying that if I have two machines with the same OS and versions it should be simply a case of using something like rsinc to keep the configs and sites identical? 
I read somewhere that MySQL supports an active passive cluster so I don't think that will cause me much of a problem. 

I know I'm not doing anything here that's all that complicated or different. I suppose the only possible issue is I'm trying to do it without spending more money on a NAS. I virtualized everything to try to keep electricity costs down. By adding more hardware I'm taking a step backword. 

Any suggestions would be welcome. 


Thanks




Darragh