Time Machine and Parallels

Discussion in 'macOS' started by SDDave2007, Mar 4, 2008.

  1. SDDave2007 macrumors regular

    Apr 12, 2007
    I do not know if this has been posted before or not...
    But I found [as have others] that it is a GOOD idea to exclude all of the Parallels .HDD files from a Time Machine Backup.

    Why? Parallels stores the entire Windows "hard drive" as a single file under OSX, and while this is transparent to the end-user, any time any "windows" file is updated [ie. everytime you do something under Windows], that ENTIRE file is marked as updated.

    My Time Machine backup had 250 gig of data on it in the first 8 hours... I removed the Parallels files from the backup sequence, and it dropped to 110 gig [and is growing very slowly]... more what I'd expect.

    There is an entire thread about this on the Parallels website as well.
  2. mmcxiiad macrumors 6502

    Jul 19, 2002
    When you back up with time machine the first time, it backs up everything (other then what is on the exclude list). After that, it only backs up the things that change. So if you open a text document and add a space in it, it will re-back up that file as a new version of it. keep making large or small changes to a file, Time machine will keep backing up the new versions. But files that have not changed don't need to be re-backed up.

    So, every time you open parallels and do anything, Time machine is going to look at the the files and say the file is changed and needs to be re-backed up. Not a big deal on small, medium or even large files. The problem is the hard drive image file for parallels is huge (usually many gigabytes) so the last thing you want is multiple backups of a huge disk image on your back up.

    really your best bet is to not back up parallels. if there are files that are inside of it that need to be backed up you can either move them to your mac's home folder and access that "drive from within parallels or manually back them up.
  3. matperk macrumors 6502

    May 6, 2004
    Milwaukee, Wisconsin
    With the way parallels is now in v3, your documents and desktop are mapped to your Mac's documents and desktop folder, so most of your files should be OK unless you run some irregular applications.
  4. mmcxiiad macrumors 6502

    Jul 19, 2002

    Yes. this is true, but if you had things in those folders (on windows) before you may want to make sure that the files that used to be in windows folders have been moved to the mac. If not, manually move them.
  5. SDDave2007 thread starter macrumors regular

    Apr 12, 2007
    Actually this is not as True as you seem to believe..... Yes while you can "map" certain documents between Win and OSX, the important issue is WHERE does the document reside. IF it resides in an OSX individual file that could be accessed even if Parallels where shut down, then yes your right, its not an issue...

    However, the issue is those documents [and Windows specific application files] that reside INSIDE the Parallels domain, which if you created them from a Windows application are more than likely in that domain.. [Parallels faciliates the ability of an OSX application to "share"].

    The point was, if you have a 128gig "Windows Hard Drive", and you open a Excel Document and change one charcter, then TIME MACHINE does not back up you Excel Document, it backs up the ENTIRE 128gig virtual volume.
  6. mmcxiiad macrumors 6502

    Jul 19, 2002
    Not to argue about symantecs, but i was trying to say that i agreed that if the folders were mapped to the mac folders (windows:my doc = mac:documents) then really the files didn't exsist on the windows machine - they were on the mac and TM would back them up.

    But if someone had a previous version of parallels and upgradeed to v3, that mapping may not have been set up as if it was a clean install.

    Ultimately between my previous 2 posts, I was saying the same thing that you did - modifing anything in parallels results in the need to back up the entire hard drive image. Thus what you wrote is what I meant.

    unfortunately, I may not have explained myself clear enough. Actually, now that i reread what you initially wrote, what I thought was a question was really you offering a Tip for everyone.
  7. SDDave2007 thread starter macrumors regular

    Apr 12, 2007
    Not a problem..... Yes I was attempting to offer a tip to everyone....

    And I can say... if I had NOT removed the Parallels files from the backup list, my 1T external drive would already be full! [and its only been running for 24 hours]

    Does anyone know how to tell how much the space used actually grows by with each backup? If you attempt to examine the folders on the TimeMachine drive... it "fakes" you out, and gives you the total that was there when it did each backup.... and I know for a fact that I havent used up 1.5T on a 1T drive [actually only 103gig]
  8. rich345 macrumors newbie

    May 7, 2010
    Back up Parallels/Windows Files

    1. It is a bad idea to allow Time Machine or other backup to copy the "file" that represents a Virtual Machine's virtual disk, because it copies the whole thing each time there is even a tiny change.

    2. In Parallels 3 it is possible to use network backup software like Retrospect to make incremental backups of individual files on a virtual machine, but you have to set up a Bridged network in Parallels and assign a static IP address to the VM, so the network backup software can find the virtual machine. (And the VM needs to be running at backup time.)

    3. In Parallels 3 it is possible to make aliases for selected folders on the VM, copy those aliases to a Mac partition, and Time Machine will back up everything inside the folders linked by those aliases. (The VM must be running at backup time.) To make the alias, have Parallels mount all volumes on the Mac desktop, double-click the desktop icon of each VM volume so you open a Mac Finder window, then make the alias there and drag it to a real Mac volume (not one of the VM volumes).

    4. Method #2 fails in Parallels 5 (at least for me) because there appears to be no Bridged network configuration available, so I can't figure out how to assign a static IP address to the VM. Thus Retrospect can't find the VM.

    5. Method #3 fails in Parallels 5 because when Time Machine starts, the VM immediately pauses, so Time Machine cannot follow links from the Aliases.

    6. I have an external FireWire drive that I could put an NTFS partition on, and run a Windows-based backup to. However, I cannot figure out how to mount a FireWire drive to a Parallels VM.

    1. Anyone know how to assign static IP addresses to a VM in Parallels 5?
    2. How to keep Parallels 5 VM from pausing when Time Machine runs?
    3. How to mount an NTFS or FAT32 partition to Parallels from an external drive connected via FireWire or eSATA?
    4. Any other good procedures for running regular incremental backups of files on a Parallels virtual machine?

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