I currently work as the single network administrator for a medium size business. We currently have 10 servers that run many different network services and apps. I am considering implementing server virtualization; however, I am a little confused about the infrastructure design necessities. My main reason to implement server virtualization is create much better disaster recovery and a failover solutions for network apps (especially mission critical apps), especially for a very small IT staff (me). My quesition is, is an ISCSI SAN really necessary for server virtualization? I was considering running two high end, beefed up servers running Xenserver (w/ Xenserver essentials) and creating a HA and failover infrastructure using that method. Other than offering more disk storage space, is an ISCSI SAN really necessary to create a virtural data center that offers HA and failover?

Might look at Sun's offering. They have most or all of that. Otherwise you can run a linux system like that. If you want that on MS get out the check book. "Best Practices", Event viewer, host file, perfmon, antivirus, anti-spyware, Live CD's, backups, Make an autorun.inf folder on all usb drives.

chris30 you are mixing clustering with virtualization. A cluster requires a SAN since there needs to be shared storage so if one cpu goes down the other still provides the path to the data. Virtualization is where you host other OS's/Apps on the same box. You can combine the two but at that point you need to go to blade servers. If the company can only afford you they can't afford blades. There are a number of standard strategies for system failover. What you choose lands somewhere between what is acceptable downtime and cost of failover. First level is mirrored/raided drives with hot spares Then there is a regular backup that is tested after each backup. Next is spare system replacement hardware or a vendor maintenance contract that replaces failed hardware in 4 hours. After these basics you get into all sorts of different scenerios. Even virtualization requires those basics to be met. So what business is the company in what is an acceptable level of downtime?