Snapshot deletion painfully slow

Discussion in 'Mac OS X Guest OS Discussion' started by milleron, Jul 22, 2017.

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  1. milleron

    milleron Bit Poster

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    I'm on version 12.2.1 of Parallels Desktop for Mac, running a Windows 10 VM. However, this problem has been present before version 12.
    On schedule, Parallels notifies me that a Snapshot is due and recommended. The program creates the new snapshot fairly quickly -- no problem.
    The PROBLEM is that it takes what seems like forever to delete an old snapshot before it starts to create the new one. The record for this is TWENTY-SEVEN minutes, but it always takes 10 minutes, at least. I can accomplish nothing during this long wait. I'm aware that I could postpone it, and sometimes I'm forced to do that, but I like to let it proceed so as not to forget to do it.
    It's just deleting an old file. WHY would it take SO long?
    Has anyone seen such a delay? Is there anything to remedy it?
     
  2. Shathish@Parallels

    Shathish@Parallels Kilo Poster

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    Hello milleron, could you please let us know the size of the Snapshots and have you tried to merge the snapshots http://kb.parallels.com/118415 instead of deleting. Thanks, Shathish
     
  3. milleron

    milleron Bit Poster

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    1 -- I've NOT tried merging (didn't know that was possible and don't understand why it would be desirable).

    2 -- How does one determine the size of a snapshot?
     
  4. rkulikov

    rkulikov Parallels Developers

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    Deleting snapshot is really a hard thing. Can you please send us a problem report and post its id here. For this in main application menu go to Help -> Send Technical Data.
     
  5. milleron

    milleron Bit Poster

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    Thank you for the quick reply. I apologize, but I do not understand what you're requesting. Isn't this thread a "problem report?" If not, what exactly is a "problem report," and how might one get its "id?"
     
  6. Hemnath@Parallels

    Hemnath@Parallels Parallels Support

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    In other words, please reproduce the issue, generate a Problem Report ID by following the steps under 'Alternative method' in this article while the issue occurs (very important) and post the Problem Report ID number in this thread.
     
  7. milleron

    milleron Bit Poster

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    Got it. Thanks!!
    I'll send it along the next time that Parallels wants to take a Snapshot. I don't want to do a manual snapshot for fear that it might differ somewhat from the very, very slow process I'm seeing with program-requested Snapshots.
     
  8. Hemnath@Parallels

    Hemnath@Parallels Parallels Support

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    Understood. We'll wait for the report ID.
     
  9. milleron

    milleron Bit Poster

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    Report ID
    202367926
     
  10. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    Hi @milleron, according to the report you've shared the virtual machine is stored on disk7, which looks like an external HDD array connected via Thunderbolt, is this right?

    Also, while deleting a snapshot the data within is not being deleted but moved to another file, that's why depending on the snapshot size (yours are from 10 to 52 GBs) the process of deleting (which, actually, merging) takes sufficient amount of time to move the data from the file which is being deleted to the parent snapshot file (according to the snapshot relation tree). The merging speed is also depends on the hard disk drive performance (HDD vs. SSD). Storing VM on an SSD disk will significantly improve both VM performance and snapshots operations.

    Judging by the above facts, I may personally assume that Smart Guard feature is not very convenient way for you to work with snapshots. May I wonder for what purposes do you use Smart Guard?
     
  11. milleron

    milleron Bit Poster

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    Thank you for that marvelous analysis. You are correct on all counts. I had no idea that data from one snapshot had to be merged with another before deletion. It all makes sense now. I can tolerate the time it takes now that I know it's not a software problem.
    Sorry, but I've no idea what "Smart Guard" is -- never heard of it. I'll research that and post a reply.
     
  12. milleron

    milleron Bit Poster

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    When I Googled "Smart Guard," I found nothing relating to computer software. Are you able to provide any clues as to what it is?
     
  13. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    You are very welcome, @milleron. Smart Guard is a feature of an automatic snapshot creation, here's the KB article about it: http://kb.parallels.com/en/5688. Feel free to ask more about this feature.
     
  14. milleron

    milleron Bit Poster

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    That explains everything. Thanks so very much! I didn't even realize that Smart Guard was a Parallels feature. Perhaps it's enabled by default. If not, I must have enabled it so long ago that the name of the feature slipped my mind.
    What I will do is to leave it enabled and simply cancel scheduled Snapshots when they are suggested if they will interrupt my work at an inconvenient time. I'll try to take a Snapshot manually at the end of my work with the virtual machine. Until now, I thought that there might be something critical about letting Parallels take a Snapshot on schedule, but you've shown me that Smart Guard is what is asking for those backups and that Smart Guard is an optional feature.
    Evem , more important was your explanation of why the Snapshots were taking so long to delete. That was my main concern. I'm grateful to know that in this case, with my hardware setup, it's not a malfunction. I can live with it, knowing that it's normal behavior.

    This was an example of absolutely superb technical support, something we don't see much any more. This experience cements my loyalty to Parallels Desktop. Thanks again.
     
  15. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    Very glad to hear that, @milleron, thank you very much!
     
  16. DeC1

    DeC1 Bit Poster

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    Just want to note that I have similar setup and am having this exact same experience, and my VM is on an SSD. So it is not disk latency. I cannot tell right now if I have SmartGuard turned on, because my parallels processes are all hung waiting for snapshot deletion... been several minutes now... so I will find out when it -- eventually -- completes. I also cannot invoke the issue reporting s/ware from the toolbar as recommended above, because the app is so hung (beachball of doom!) that I cannot pop up the tool bar.

    I would like to note also that the Snapshot Deletion progress seems to go backwards at times, which is quite disheartening for the naive observer :) my progress indicator has got up past 50, only to fall back to 14 and then painfully crawl forward again. If we are stuck with these occasional awfully slow episodes it would be nice to have a more realistic progress bar...

    I have been backing up my VM with Time Machine so I don't see why I need a separate Parallels backup scheme... I thought I had Smart Guard turned off, but if I accidentally turned it on I will certainly now disable it.
     
    Last edited: Jan 28, 2018
  17. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    Hi @DeC1, to be able to help we need a technical report from your Mac, preferably during snapshot deletion. Please go to Help menu > Send Technical Data... > generate and send the report > post its ID here please.
     
  18. James Rome

    James Rome Kilo Poster

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    You can only delete snapshots going forward. This takes hours to do all the snapshots. Isn't there a way to delete all snapshots quickly?
     
  19. Dmitry@Parallels

    Dmitry@Parallels Staff Member

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    The time needed for snapshot deletion depends on Mac's hard disk performance and the amount of data that needs to be synchronized between the files. Do you have an SSD disk or a rotational HDD? Unfortunately, you can't delete all snapshots in one click.
     
  20. James Rome

    James Rome Kilo Poster

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    107
    VMs are on a USB3 drive actually. Is there a way to just delete the snapshot files? Why isn't there a way to delete all snapshots and start afresh? It would seem easy to do...
     

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