Guest OS upgrade, would this work?

[gudel]

I have a Win 2003 R2 x64 guest in ESX 3.5. This VM is a file server VM, I have two disks in it, one is for the OS and one is for file sharing. I would like to upgrade the OS into Win 2008 R2 x64.

I was thinking to build another VM with 08 in it, and add the 2nd drive by using the 'use an existing virtual disk' option when creating a VM.

I only need the 2nd drive as it has all of our files, and don't really have anything in the server as all it does, is just to share files.

Is this a good way to upgrade guest OS, create another VM and add a disk from an existing virtual disk?

[mittim12]

If you want a clean install that may be the way to go.  You could always create a snapshot, upgraded the current, and revert if you have any issues.