I've been asked by my boss to investigate making our own high availability systems at our data center to avoid the increasing costs of managed hosting.
We currently have a couple of DNS servers, a few dedicated web/sql servers, a few shared webservers and a few shared SQL servers. Since the process of clustering (or more likely load balancing) the webservers has rather different challenges, my question pertains to how best to make a small SQL cluster without a single point of failure.
Messing around in VMware I've setup a DC and two servers and begun to cluster them, it seems I'm going to be able to do this. However I achieved my setup by pointing both machines to the same virtual disk on the host OS. Good for my test environment, bad for working out what my production needs will be.
I have not found a definitive answer, but it seems that HA resource storage for ones cluster is never(?) done on the actual servers themselves, rather on the somewhat cryptically mentioned "external disk arrays" wherever I look.
What I need is a decent solution for this. If one can store the SQL data on the clustered servers themselves (maybe with SQL replication?) then that's probably what I'm after.
However I think I need a reliable external storage solution. This area is rather new to me as an administrator designing this system so I've researched a number of solutions.
1. SCSI storage devices. Presumably RAIDed. However I've read these only do fail over and don't support different machines writing to them. Also I'd need power redundancy.
2. iSCSI or Fibrechannel. I assume using some software or other to first create some file storage redundancy across a couple of servers, then addressing these devices over the network from the cluster.
3. NAS box. Opinion seems to be against using as NAS for clustered storage but I'm keen because I could get a solution in a box if this were suitable.
Something like this with redundant everything, or would I still be putting my eggs in one basket if so?
4. My own NAS. I have quite a few servers to play with, no high speed connectivity as of yet though. Would yet another cluster to cluster a file server be the way to go? And would I need some fast cabling to make this viable in any case?
So in conclusion, I have no idea what kind of storage is required for this SQL cluster I'm researching, could someone demystify the subject at all?
Windows Server 2003 Cluster with SQL 2000.