Time Machine make no sense when you run VM's on your OS X ?

Discussion in 'Windows, Linux & Others on the Mac' started by macenied, Oct 12, 2014.

  1. macenied, Oct 12, 2014
    Last edited: Oct 16, 2014

    macenied macrumors 6502a


    Aug 20, 2014

    I recently started to use VM Fusion 7 on OS X 10.9.5, mainly to learn more about it's capabilities on my MBP.

    Now I see that every, even tiny change on a virtual harddisk causes Time Machine to backup the entire virtual drive of the VM. While this technically make sense to me, it is nothing what I really want or would recommend. This means frequent backups > 10 GB every time when I use(d) a VM.

    How do you deal with this ?
  2. Phil A. Moderator

    Phil A.

    Staff Member

    Apr 2, 2006
    Shropshire, UK
    Just exclude the VMs from time machine and backup anything inside them (I.e run the backup tool within the VM) using something else (such as crashplan or native backup tools
  3. maflynn Moderator


    Staff Member

    May 3, 2009
    You need to exclude the VM from backups or you're back up drive will fill up fairly quickly.

    It makes sense since even booting up, causes the container file that is the VM to be changed (at least by TM's perspective), so it will back up the entire container file.

    I manually back up my VM, by copying it to the external drive and let TM just do its thing for everything else.
  4. SandboxGeneral Moderator emeritus


    Sep 8, 2010
    Like the others said, exclude the back up from Time Machine. Thats what I do too.

    I don't back up my VM's at all just because if I lose them, I don't care. There isn't anything in them that I need per se. But if I did need them, I'd back them up another way, not using TM.
  5. grahamperrin macrumors 601


    Jun 8, 2007
    I use ZFS to store .vdi files and so on for VirtualBox. And ZFS to store backups, including Time Machine backups.

    Less exotically: before I shifted to ZFS, I used sparse bundle disk images to store the large files. A limitation with this approach: ensure that some backups occur whilst the .sparsebundle is not attached (whilst the volume is not mounted); and know for yourself how to identify those backups.
  6. macenied thread starter macrumors 6502a


    Aug 20, 2014
    Thank you all for your help !

    I will exclude the VM disks from TM now and will make a cold backup of them in case I need it.

    I did not want to give up TM because other than my issue now it works very good for me and I even can perform a full restore of OS X without any issues.

    All good again :)
  7. glenthompson macrumors 68000


    Apr 27, 2011
    I store all my Windows data within the Mac data space so it gets backed up with Time Machine. My VMs rarely change so the occasional copy serves as a suitable backup. Another trick is to setup your VM the way you want, activate it then make an archive copy. If you ever have to rebuild Windows you can just copy back the archived copy and not have to go through the deactivation. Also handy for creating test and production versions on a single license.
  8. hfg macrumors 68040


    Dec 1, 2006
    Cedar Rapids, IA. USA
    I exclude my Windows VMs from the hourly Time Machine backups, but I also have CCC scheduled to do a daily clone copy of my boot disk which includes the large VM images.

    In the event of significant Windows updates, I will temporarily remove the VM directory from the "exclude" list and allow a single Time Machine backup to capture the current state, then I will replace the VM directory in the "exclude" list to avoid continuous backup.
  9. macenied, Oct 15, 2014
    Last edited: Oct 15, 2014

    macenied thread starter macrumors 6502a


    Aug 20, 2014
    Hmm ... while I like Time Machine ( mainly for it's full restore capabilities ), I'd like to set it up according to my requirements:

    - Make a daily ( or upon request ) backup of the entire OS X partition ( full backup )
    - Compress backup files
    - Keep 5 ( or any number ) of these backups, after that delete the most outdated backup
    - Verify backup ( compare backup files with files on OS X disk )
    - Restore disk, folders = directories or files from any stored backup
    - Don't do anything more ( I don't need hourly backups, etc. )

    Can Time Machine be configured like this ?

    Thank you in advance for your reply.
  10. hfg macrumors 68040


    Dec 1, 2006
    Cedar Rapids, IA. USA
    Time Machine doesn't do discrete full backups, other than the first one. The hourly backups only include the files which have been modified, i.e. an "incremental backup". It will keep historical versions of your files up to the limit of the backup disk capacity. When you reach full capacity on your backup disk, Time Machine will only discard the oldest files which are redundant, it will always keep at least one copy of every file and will alert you when it is unable to do so. You can restore to a desired date either individual files or folders, or the entire state of the computer on that date.

    You can also use a program like CarbonCopyCloner (CCC) to keep a "non-historical" copy of a disk image. It too can be configured to only do incremental file copies to save time, but you will have a simple 1:1 clone of the source disk. There are additional modes which can be selected within CCC for different results.

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