Restoring Windows standaloneVM from backup

qun · March 3, 2022, 5:47pm

Hey!

Are there any known problems of restoring Windows StandaloneVM from the backup? I can not start the restored one. Just get blue screen and then: qrexec-daemon.c:135:sigchld_parent_handler: Connection to the VM failed.

Best regards
qun

fsflover · March 3, 2022, 6:29pm

github.com/QubesOS/qubes-issues

Migrate backups of Windows VMs created under Qubes R4.0 to R4.1

opened 12:28PM - 26 Nov 21 UTC

closed 08:41AM - 15 Apr 22 UTC

GWeck

T: bug C: doc C: windows-vm P: default diagnosed affects-4.1

Qubes R4.1-rc2 ### Brief summary Windows 7 / 10 / 11 VMs (Standalone / T…emplate AppVM) restored from a backup of these VMs created under Qubes R4.0 cannot be started under Qubes R4.1. - Windows 7 starts without displaying a window, no matter how the `gui` and `gui_emulated` values are set. After some time (a minute or so) the VM stops without a message, but the Qube manager still shows it as starting (yellow dot). - Windows 10 or 11 first start normally, but then crash with the error `Inaccessible Boot Device`, which can mean almost anything but probably is caused by a hardware representation that is different from that under Qubes R4.0. This behaviour is independent from Qubes Windows Tools being installed in the VM; it occurs with and without QWT in the same way. ### Steps to reproduce In Qubes R4.1, restore a backup of an Windows VM which was stored under Qubes R4.0. After the VM is created, try to start it. ### Expected behavior If the VM does not contain Qubes Windows Tools, it should start the same way that it did under Qubes R4.0. With QWT 4.0.1.3 installed, it should start with a non-functioning QWT and allow to replace the Qubes Windows Tools with a version suitable for Qubes R4.1, e.g. QWT-4.1-65 from @jevank [tabit-pro/qubes-windows-tools-cross ](https://github.com/tabit-pro/qubes-windows-tools-cross) ### Actual behavior The VM crashes after start. No real recovery is possible: - For Windows 7, no action can be taken. - For Windows 10, after letting the VM crash several (3 or so) times, an automatic repair is started, but never terminates (a well known bug of Windows 10). So far, I found no way of disabling this automatic repair, and trying to change anything via the command console had no effect. The option to start the VM in protected mode is not offered, so you are stuck with the non-working automatich repair. - For Windows 11, the behaviour is similar, but the automatic repair really does some repair and then allows to start the system in protected mode. After the next reboot, the system seems to run normally. **But:** If QWT 4.1-65 is installed, which runs o.k. in a VM created under Qubes R4.1, it does not work in the VM created from the R4.0 backup. The two service processes are running, but file transfer to/from this VM does not work, indicationg that the `qrexec` interface is not really up. Also, if a restart of these processes is tried, it just times out, and the processes do not shut down. (In a VM newly created under Qubes R4.1, they can be shut down and restarted.) It might be helpful to know what type of hardware a Windows VM does see, and how this differs between Qubes R4.0 and R4.1. Windows seems to rather fragile in this respect, in contrast to Linux-based VMs which can be well restored from backups created under R4.0.