Total VM Restore Failure

Discussion in 'Windows Virtual Machine' started by J_Semp, Feb 6, 2013.

  1. J_Semp

    J_Semp Bit poster

    Messages:
    9
    I have a rather large predicament on my hands.

    I run SolidWorks (3D Modeling Program) on a MacBook Pro (Mid 2012) running Parallels 8 for mac.

    I was drafting in the program, exited and decided to reboot my mac to free up some ram.

    Upon restart, SolidWorks returned a Fatal Error within the registry. So my first reaction is to uninstall, then reinstall.

    Well that failed when the Windows installed gave me an error 5% into removing the program. And of course, Windows thought that the program had been totally uninstalled. I could not re-run the uninstaller, nor could I install the program over again, I just kept getting errors.

    I decided to reboot and try again, and this time Windows wouldn't boot. No matter what I did, Startup Repair would run, detect problems, take an hour to "attempt" to fix them, then tell me that the problems can't be fixed automatically.

    So my next step was to use a Time Machine backup of the Windows VM file. That didn't work either.

    I am beginning to go insane...

    So now I am being forced to create a new VM and start from scratch. I am extremely disappointed that the Time Machine backup of the VM is totally worthless, and more disappointed in the fact that Parallels has done NOTHING to create a reliable, FAST and EFFICIENT way of backing up your VM.

    Has this happened to anybody else? Or is this a totally unique scenario...
     
  2. Specimen

    Specimen Product Expert

    Messages:
    3,236
    It would be important to know if this is a Bootcamp based VM or a 'pure' Parallels VM.

    If it's Bootcamp based, Time Machine cannot back it up, you have use use a Windows backup solution, or Winclone (google it). Also, if it's Bootcamp based, any programs that requires close ties with hardware should be installed/unistalled while in Bootcamp (booting natively).
    Finally in this case, what TM backs up is the .pvm package (all the settings for Parallels) but not the disk itself, as it is a real partition.

    If it's not Bootcamp based, the best strategy, in my opinion, to back up a VM is to just copy the .pvm package to a safe place, and drop it back when needed.

    It would also be important to know if the VM was properly shut down or not or if it was suspended, snapshots or no snapshots.
     
  3. J_Semp

    J_Semp Bit poster

    Messages:
    9
    The VM is not Bootcamp-based, it is a true VM.

    The VM was properly shut down. No snapshots (this feature takes WAY too long to be the efficient way of backing up a VM).

    Isn't the Time Machine backup file essentially the same thing as copying the .pvm to another location for safe keeping? I can browse directly to the file and restore it, which is just copying the backup file and replacing the old one.
     
  4. Specimen

    Specimen Product Expert

    Messages:
    3,236
    No, it is not the same.

    First, pvm is not a file, it's a package/folder that includes all the files that compose the VM (settings, logs, virtual disk, etc). Secondly TM only backs up the files that are different from before, the way this operates with Parallels virtual disk can be tricky, as a change in the disk, which is a file for TM would mean the whole disk file (several GB) is to be backep up (you would quick run out of space) the method Parallels uses to just save incremental data with each backup (so TM doesn't the whole disk every time) is via snapshots.

    So no, it's not the same at all, not from the complex process behind backing up point-of-view, which may influence restoring.
    Personally i don't allow TM to back up my VMs, they are manually backep up from time to time by copying the pvms.
     
    Last edited: Feb 7, 2013

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