Parallels 15 destroyed EFI partition

Discussion in 'Installation and Configuration' started by RozhkovI, Aug 14, 2019.

  1. RozhkovI

    RozhkovI Bit Poster

    I had 3 OS on my Mac via Fefind (OS X, Win, Ubuntu) and everything worked fine with trial parallels 14 !

    After I installed Parallels 15 and first time run bootcamp-based windows 10, Parallels 15 asked me to reboot my vm after Parallels tools upgrade.
    Then vm can not start as it can not find loader!? I checked my EFI partition and found that there is no any data in it. Wow!

    So now I have no access to my bootcamp-based VMs and thanks god I decided to check EFI partition and reinstall refind. Or I would loose access even to OS X boot.
    Parallels is so parallels. After many years with VMWare I decided to try it and "welcome", "enjoy".
    How broken is 15 version if it can destroy data on Efi partition???????
  2. Maria@Parallels

    Maria@Parallels Parallels Team

    @RozhkovI could you collect a tech report data and reply us back with the report's ID?
    We will investigate this issue further
  3. Dmitry@Parallels

    Dmitry@Parallels Staff Member

    Hi @RozhkovI, Parallels Desktop does not have write access to EFI partition by default, read only. But, if you have System Integrity Protection disabled and you're using custom boot loader, Windows might break its structure. I repeat - Windows updates EFI partition when there is read-write access.
    Last edited: Aug 15, 2019
  4. RozhkovI

    RozhkovI Bit Poster

    Dear Maria and Dmitry,
    I did some research and ready to send some info for you

    and What?
    "Parallels client-programs aka Operative systems" have it. So this is still your problem to control it if these systems operate in a differ way then usual during Parallels booting.

    1. Moreover, Parallels do it - for instance if you will try to install Ubuntu on Physical drive and choose EFI for boot loader, then you will see message from parallels that operation is not permitted (but if you will install Ubuntu from demo interface - then Parallels is ok with EFI write LOL)
    2. System Integrity Protection disabled - yes as I had before problems with both Parallels and Vmware because in was enabled - well known problem for you guys. Maybe this version is not mandatory to switch it off. I don't know.
    3. I never saw as well as I could not google info that Windows 10 delete all files from EFI without writing any data. Is it strange? I am more then sure that this is so critical issue to remove all booting data, that MS programmer... any programmers can't do it in purpose.

    Possible reason:
    The only one thing that got changed "visually" after upgrade from 14 to 15 is HardDisk --> Advanced settings --> location:
    Before upgrade I had Sata 0:1, after NVMe 1. Maybe at some step Parallels allowed Windows to make changes(delete), then disallow(update) without any notification. Example with Ubuntu installation above - we can see that Parallels blocks EFI access only sometimes! (make it always then or do backups or ask password or whatever?)

    Also, I have EFI backups. So if you are interested in problems solving, tell me how can I share these files to you:
    1. before upgrade from 14 to 15.
    2. Now (when I finally fixed the problem) and both Windows and Ubuntu worked normal way
  5. Dmitry@Parallels

    Dmitry@Parallels Staff Member

    Thank you for the details, @RozhkovI. Can you please send us a technical report via Help menu > Send Technical Data... > please post the report ID here.
    Parallels Desktop does not control whether to allow Windows to write to EFI partition or not. When SIP is disabled on Mac, Windows can write to EFI partition.

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