So I’ve been tasked with doing tech-support for a relative on a different continent because his rather important work-data has suddenly become inaccessible
The basic situation is that his virtual image of Windows XP has become un-bootable using parallels (he is getting a relatively general BSOD message) and we’re wondering what are options are.
I don’t think he is in the habit of using parallels to save “states” of the VM (I think that is some sorta built-in back-up system) however he does have a Time Capsule that backs up the whole HD on an hourly basis.
So I’m thinking the easiest solution would be to use Time Machine to restore the virtual disk image to a time before it got corrupted. Is there any reason this isn’t likely to work? If it is a good idea, can anyone tell me the default location (or typical file name or extension) for this image file?
If the above strategy isn’t viable, would using the ‘repair’ or ‘safe-mode’ boot of XP help?
Here’s one reason the Time Machine strategy might not work. I use Fusion, not Parallels, but they’re both very similar. By default, Time Machine does not back up the Fusion disk image as it sees it as a new file every time Windows updates even the tiniest file within the image. So the end result is that you fill up your backup drive very quickly copying and recopying the entire disk image every hour it’s in use.
So Time Machine doesn’t do partial file backups? That sucks. Still, you may be able to use the (inferior) XP equivalent–System Restore, but you’d have to get into the system first. I don’t know how easy it is to use a boot disk in Parallels. Using safe mode probably won’t work, but you should definitely try repair mode, at least.
Are the virtual machine disk images proper disk images? If so, then you should be able to mount them into the filesystem, and then access the files that way. You may not be able to actually repair the disk, but you can copy out all the important files, and then delete and reinstall the entire system, and then copy the files back.
Sorry this advice isn’t very much on the specifics–I don’t own a Mac, and am basing this on my experience with an old G4 Mac at school, Linux, and other virtualization software. A real Mac user would have to help you with the specific commands.
Yes, a repair on a virtual machine is just like a repair on a real machine. If you just need the files you may be able to find a file viewer that can read that image file and pull the files you need. I know these exist for VMWare and VirtualBox, but I have not had much experience with Parallels. This is really a question for Parallels support. You should contact them before you make ANY EDITS OR RESTORES to the drive. At the very least research what files you need and back them up asap.
Parallels does provide a utility to view the contents of a virtual hard drive… but if it is too corrupted to boot up, that might not help.
You can restore Parallels virtual computers by making copies of the files and then restoring those. In fact, that’s exactly how my office does it. We have three XP virtual computers. If we have any technical issues with XP at all, we make a copy of the virtual hard drive from a good virtual XP, replace the bad virtual XP and then update some simple information to get it up and running (IP address, registration numbers, etc.)
So the question is just whether Time Machine gave you a copy. If so, it’s a simple drag-and-drop operation to get it back to an old version.
I just had a look, and on my Mac, the main VM file for Parallels is in
/users/myname/library/parallels/winxp.pvm and there’s what’s described as a backup at /users/myname/documents/parallels/Microsoft Windows XP (Backup)/winxp.hdd. I think this may actually be a pre-upgrade image as it’s several months old.
Both are being backed by Time Machine. If you hit the Configure option on the Parallels desktop before you start the VM, the General tab has the option for not backing it up.
