I was recently speaking with a few clients who were both complaining about slow performance under Microsoft Virtual Server.

After reviewing their setups, I realized they missed a few common optimizations.

As with any virtual server enviornment, make sure your host is tweaked and optimized before you blame virtualization.

There are easy best-practices which we have been following for years which are easily the most overlooked items.  You'll have the fastest Virtual Server if you follow these recommendations.

• Update All Firmware

  The #1 overlooked item.  And it has the most impact.

  Every device in your Virtual Server that has a firmware needs to be verified that its running that latest (stable) version provided by your vendor.

  If you have a whitebox or other non-big-3 server (HP, IBM, Dell) than this can take some work.

  But get this done.  It helps so much.

• Disable all NIC Offloading

  Every NIC on your system should be manually verified to disable ALL offload options.  Different adapters call these options by different names, but if the setting has the word "offload" in it, turn it off ;)

  Years ago we found this out by seeing frequently corrupted virtual disk images.  Luckily Microsoft Virtual Server has stablized a lot since then and now its just a performance drainer.

  More info and gory details at: http://support.microsoft.com/kb/888750

• Use SCSI virtual disks instead of IDE

Without a lot of tech mumbo, IDE virtual disks should never be used.  They are slow in the physical world and guess what?  They are slow in the virtual world too ;)  Stick with SCSI.

If you've added your disks as IDE already, the following steps should get you converted:

• add the virtual SCSI adapter to your VM and restart it
• reinstall the VM Extensions and make sure the Virtual SCSI adapter is there
• reboot the VM again to be safe
• remove the existing IDE Virtual disk and readd it as a SCSI disk
• Run the latest version

  This goes without saying, but no list would be complete without it.  Run the latest version of Virtual Server.  We're running the latest beta at all our clients with no ill-effect.  If you're not that brave, than run the latest release.  Virtualization is "new" technology that is moving quickly.  It really helps to stay up to date.

I've been looking for a way to convert images made for VMWare over to Microsoft Virtual Server or Virtual PC.  I finally found something: http://vmtoolkit.com/files/folders/converters/entry8.aspx.  Sweet!

One caveat - this doesn't work with Linux VMWare images.  Darn.

Please Microsoft, release the Linux compatible version of Virtual Server!!  I'm running the beta but until its released, none of the linux folks will take Virtual Server seriously ;)