Reinstalling Fusion 8 and Virtual Machine after clean re installation of OS X

[Wammer]

My iMac has been performing sluggishly since upgrading to Yosemite so I plan a "clean" re installation of the OS and all my apps i.e. I shall not be using migration assistant.  My question is this: when reinstalling my Win8 virtual machine do I simply reinstall Fusion and copy across my Windows 8 vm file from a backup, or is it more complicated than that?  Win8 is an upgrade from an OEM XP and I have licence keys for both but I would naturally prefer not to have to reinstall from scratch if I don't have to.

[dariusd]

If it happens to be a Mid-2011 iMac, you might want to check out this thread: Yosemite and Fusion 7 - Very Very Slow

If you have a good backup of your virtual machine, it should just be a matter of reinstalling Fusion, restoring the virtual machine bundle from the backup, and either double-clicking on the virtual machine in Finder or opening the file from within Fusion.

General opinion seems to be that Time Machine really doesn't handle virtual machines terribly well at all.  I have heard reports that it is possible for it to work if you power off the virtual machine and quit Fusion entirely, but I have heard way, way more reports of it just not working at all and ending up with a corrupted backup... I (personally) wouldn't risk using Time Machine to back up an important virtual machine without thoroughly validating it, but I guess that would apply equally to any other backup solution.  If you have trusted backup software, use that, and/or copy the powered-off virtual machine off to external storage for the time that you do the upgrade.  (For the record: I don't have any preferred backup program.  I live life on the edge.  Well... OK, really, all my virtual machines are pretty much disposable and aren't worth backing up.)

Good luck!

--

Darius

[Wammer]

Thanks Darius, mine is an early-2011 iMac and the problem is not with Fusion but with the Mac generally, which is rather sluggish and locks up or crashes a lot since upgrading to Yosemite.  Yosemite is the third successive "over the top" OS upgrade and my gut feel before I upgraded to Yosemite was that I should do a "clean" install, so I think I shall take advantage of the Christmas break to reinstall from scratch.

Nice to know that I can simply reinstall Fusion and copy across my vm from a backup.  I don't use TM for vm backups, I use either Finder or ChronoSync.  Like you, if I had to reinstall the vm I wouldn't lose anything important, apart from a few hours of my life!