Time Machine backups only of the snapshots

Discussion in 'Installation and Configuration of Parallels Desktop' started by JedrzejO, Sep 29, 2018.

  1. JedrzejO

    JedrzejO Member

    Hello everyone,

    When I am working on Windows guest with time machine running the backup disk will fill up pretty quickly. I have the Smart Guard option with Time Machine optimisation activated, so it helps a bit, but I wanted to know if it is possible to force Time Machine to backup only the snapshots? My idea is, I could exclude the main VM drive file from the time machine, and only the backups of the snapshots in different directory would be running.

    Is it doable? I didn't see any convenient option to define where the snapshot is created. Maybe there would be a different way for even better optimisation?
  2. Hemnath@Parallels

    Hemnath@Parallels Parallels Support

    Hello JedrzejO.
    Technically, keeping 'Optimize for Time Machine' enabled does mean that only the latest snapshot is being backed up.
    Again, 'Optimize for Time Machine' helps you in this regard.
    The snapshots' location is within the virtual machine file bundle (the file with the extension '.pvm') itself.
  3. JedrzejO

    JedrzejO Member

    Thank you for your reply! I have this option already on, I was wondering if I can optimise it any further in the described way. My external disk for Time Machine gets filled up pretty fast anyway.

    So I guess there is nothing to do here.
    Last edited: Sep 30, 2018
  4. Unfortunately, there is no option to backup the snapshots flie separately from the pvm bundle.
  5. RaphaelF1

    RaphaelF1 Member

    Hi all. I know the thread is kind of old, but I just wanted to share with you guys my response in another thread that may shed some light on the situation. Please note that in the thread where I posted this before, the original poster had a question related to using the client's own encryption. Hence the part where I talk about the encryption.

    As to Sathiya@Parallels's comment "Unfortunately, there is no option to backup the snapshots flie separately from the pvm bundle." Why would you want to do that? Please read on for possibly some answers.

    Here you are. I hope this helps.

    ...myself, having struggled with the pairing of TimeMachine and Parallel's SmartGuard snapshots, and the very poor documentation on the subject, decided to share what I discovered. Basically I needed to truly understand how the snapshots worked, and if I could rely on them in case I ever needed to restore a VM from a snapshot using TimeMachine (and the snapshots). In other words, I had the same "Sub-question" that you had, and then some.
    So, here it goes...

    First, disclaimer: I do NOT work for Parallels and I am in no way, shape, or form the final authority on the software. I did do extensive testing though, and the results of all my testing, which involved going through several iterations of waiting for snapshots to be automatically created, and test recovering the VM several times using TimeMachine, at different stages (with no snapshot yet taken, with 1 snapshot taken, with two, and more snapshots taken, with both the VM powered on and off), AND, yes, my TimeMachine drive IS encrypted.

    I'll first give you the bottom line of all my testing, and then I will expand.

    Bottom line: Yes. It all works. Perfectly. Seamlessly.

    Now, you're thinking "That does not answer any of my questions!" But it does. In an Apple philosophy kind of way... As in, Apple (and in this case Parallels) says you do not need to know, so you do not need to know. Of course, we The Users disagree. We DO need to know.

    So, here's my expanded answer:

    1- I will put this one first, because you mentioned you are doing the encryption in the guest. That presents the problems you mentioned. You actually can keep on doing that. But, if you really want your data and your backups safe, and you want the final results that you described, you need to (also) encrypt your TimeMachine backup drive itself. Yes, I am saying that if you want to have your VM encrypted at the guest level, and you want your backup safely encrypted when the VM is powered on, you must encrypt your TimeMachine drive backup as well (host level). If you do that, it really does not matter if the VM is powered on or not. The backup will be encrypted on the backup drive (TimeMachine), and you (or anyone else) will only be able to restore the VM to that specific powered on state (and access any sensitive data) if they have the decryption password of the encrypted TimeMachine backup drive. Makes sense? (Yes, I know you will be encrypting twice here. But that's the price you pay for what you want to achieve.)
    2- Number one pretty much takes care of your encryption situation. Now on to how SmartGuard Snapshots actually do work really well with TimeMachine... I thoroughly tested each and every single scenario I mention here:
    a) If there aren't yet any SmartGuard snapshots of the VM: TimeMachine backs up the entire .pvm file, however large it is, regardless of whether the VM is powered on or not. Again, if you have the backup drive encrypted, you are safe, even with the VM powered on.
    b) If there is already 1 SmartGuard snapshot, AND TimeMachine has at least one full backup of the entire .pvm file, THEN it keeps the full .pvm backup, does not back it up again, and backs up the snapshot.
    c) If there is already 1 SmartGuard snapshot, BUT TimeMachine never had a chance to backup the entire .pvm, THEN it backs up the full .pvm, AND then it backs up the snapshot.
    d) And the pattern repeats itself... If there are 2 or more SmartGuard snapshots, TimeMachine will back up the full .pvm file only if it wasn't backed up before, and it will do the same for any SmartGuard snapshots that it hasn't yet backed up. That is, if the snapshot has already been backed up before, it is already backed up, and it is not backed up again. But any new snapshots that weren't yet backed up WILL be backed up. However many (non-backed up) snapshots there are.

    If you follow my reasoning 1 thru 2, a thru d, you see that everything gets backed up, quite efficiently, without data duplication.

    Now you may ask (I did!): "Ok. How does the restore work?" That was my main question, because I wanted to make sure I could rely on SmartGuard and TimeMachine configured this way. It is quite simple, actually. When/If you want to restore, you simply enter TimeMachine, browse to the folder that contains the .pvm file, and click "Restore". TimeMachine/Parallels SmartGuard will automatically calculate which SmartGuard Snapshot was the closest one taken prior to the TimeMachine backup and restore the main first full .pvm backup, and then apply the latest SmartGuard Snapshot, which will bring your machine to the closest state it was in, when the last snapshot was taken, before the last backup was taken, for the date that you choose.

    Practical example:
    1- TimeMachine runs and backs up your entire .pvm, say, 01/01/2030.
    2- SmartGuard takes a snapshot 01/02/2030.
    3- TimeMachine runs and backs up the 01/02/2030 snapshot on 01/03/2030.
    4- SmartGuard takes a snapshot 01/04/2030.
    5- TimeMachine runs and backs up the 01/04/2030 snapshot on 01/05/2030.
    5- SmartGuard takes a snapshot 01/06/2030.
    6- At this point, on 01/07/2030, you experience a catastrophic failure of your drive and you lose the .pvm completely.
    7- After resolving the problem with the drive, you enter TimeMachine, browse to the folder where the .pvm file resides. Go back in time to 01/06/2030, and you click restore. TimeMachine knows it has a good full backup of the .pvm from the first original backup, and it also knows that the latest available backed up SmartGuard Snapshot for the date you chose (01/06/2030) is from 01/04/2030. It restores the .pvm file exactly as it was as of 01/04/2030, which is the latest good backup/SmartGuard Snapshot combination per the restore date chosen.

    I know I typed a book here. (And I am not the best writer :)) But I hope I explained everything.

    Best, Raphael

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