To Virutalize or Not To Virtualize
Posted on 2006-11-14
I'm looking for some advice on whether or not to migrate from physical to virtual servers, and hope that some of you out there have some experience with virtual servers and can let me know if they are an option for me to consider or not.
At present, I'm preparing to replace our existing servers, upgrade them to Windows Server 2003, and probably set up a new, off-site, disaster recovery (DR) server. We currently have three physical servers set up as follows:
Exchange front-end for OWA
We'll need all of these function on the new servers PLUS Microsoft SQL Server (for light duty apps) and some type of anti-spam front-end for Exchange.
Because of space/cost considerations, I really don't want to add any more machines (not counting the DR server). So I've been considering migrating to virtual servers so that we can use 2-3 physical machines but have more virtual machines. These are the pros and cons of moving to virtual servers as I see them:
- I can separate functions better. For example, I could separate our domain controller from other functions or separate Exchange and SQL server onto "different" servers.
- Setting up the disaster recovery server would be quite easy in that I would just restore the necessary VMs onto the DR server.
- Hardware maintenance or replacement would be much easier (though this has not been a big issue for us in the past).
- The extra complications involved. Learning about and setting up virtual servers may not be worth the trouble. Also, I'm a one person IT department with business operations people as backup, and the simpler for them (and me!) the better.
- It may not save us anything in hardware costs as we may wind up with the same number of physical servers and/or require higher end servers to run the VMs.
- Backing up may be more involved as we'll need "regular" backups of data from the VMs for restoring deleted files, etc. and a backup of the VM itself for disaster recovery purposes.
- I've read that running DCs and Exchange on VMs is not a good idea because of performance.
Note that we only have about 15 users, and usage of most of the Windows services other than e-mail is fairly light (our main application runs on a separate Unix server).
So what are your thoughts on this? Are virtual servers a good option for us or not, and for what reasons? Any positive or negative experiences doing something similar?