We're a small business (about 10 people) looking into a virtualization setup mainly for disaster recovery reasons, but also for backup and possibly some server consolidation capability in the future. I've done some research into the products, and have used VMware for desktop virtualization for some time. What I'm interested in using, though, is some bare-metal hypervisor setup, rather than something host-dependent, like VMware Server.
Cost is a major concern of ours (surprise, surprise). We have 2 physical servers currently: one is SBS2003 for DC/Exchange/printers, the other is for data shares/Backup Exec. We're on the cusp of getting a lot of new work (which will mean more people) and are looking to invest some money in new hardware/software, so I want to take advantage of the opportunity and do things right. The plan so far is to buy 2 new servers, each with some "type 1" hypervisor running 1 VM on local storage. We'll also probably upgrade to Server 2008 and Exchange 2007 as part of this investment. The disaster recovery conveniences of virtualization are attractive, and a proper setup would ready us to run multiple VMs on each host, et cetera.
Here are some questions I have:
- What kind of hardware do we need? - I assume some type of x64 configuration with lots of RAM...
- Hyper-V vs. VMware vs. other?
- Costs associated with hypervisor software?
- How do we create full backups of each virtual server? We currently backup to one of several large hard disks, rather than tape...
- Server storage? - is my idea to use local storage on each physical server for the VMs a sound one? We definitely cannot afford a SAN or some other shared storage.
Any 64-bit hardware Intel/AMD should work just fine. I prefer AMD for lower costs and energy savings, but it's a matter of taste these days. I wouldn't worry so much about CPUs these days as long as it's the latest releases from Intel/AMD and just make sure to get as much memory as possible. It could be argued that memory is probably more valuable in virtualization that CPU cores these days.
Other: Citrix XenServer 5.5: it's perfect for small businesses just starting out with virtualization. The free version offers more features than Hyper-V or ESXi. Simple, easy management interface that comes with. I use/recommend it more often these days than ESXi.
The big 3 vendors: VMWare, Citrix, Microsoft all offer basic hypervisors essentially for free. The costs come in for additional features that don't come bundled with the free version. VMWare is the most costly but most robust for the true enterprise large-scale environments. At this point in time it sounds like your small business will not likely need those enterprise features down the road. Citrix's offerings are comparable to VMWare but I would argue not nearly robust or mature as VMWare or as costly. Hyper-V is the newest player on the market with relatively low cost and probably the least mature but is quickly gaining ground.
Each solution typically has their own backup methods. VMWare has numerous 3rd party vendors sell their solutions. I'm unsure of Citrix or Hyper-V offerings but all of the virtualization vendors have ways of creating backups of guest VMs. There are "free" ways of creating backups but they may take some hackery/trickery and some tinkering to get it to work. I'm sure plenty of users here are aware of different methods of backing up VM guests given a type of VM host, but I don't want to delve into the numerous ways of backing up as there are numerous posts on the subject.
Since you can't afford SAN storage, you could look to the cheaper iSCSI based solutions as VMWare, Citrix do work with iSCSI. I can't speak to Hyper-V as I seldom use it so I'm sure others on SF could comment on it. If you can aim for shared storage, whether it be a simple iSCSI solution or not, try to do it if and only if for VMotion/live virtual migration in the future. If you can't do it, just make sure to use solid hardware RAID controllers and find ways of backing up the images frequently.
After working through your questions, if you ask me on what to do about your situation, I would consider either Citrix XenServer or Hyper-V. VMWare is great, solid, mature and possibly overkill for the future. Granted they have numerous product offerings at different price points, I think Citrix and Microsoft give you the best choice in terms of free offerings at this point in time. Your storage situation/budget will probably affect you more than which virtualization vendor you go with as live migration is a huge feature of virtualization. I would probably scale down the actual virtual hosts to invest in some shared storage if it's an option at all.