Tip: Restoring functionality of Windows AppVMs after a crash or forced termination

[Grzesiek Chodzicki]

After a Windows AppVM running in Seamless Gui mode crashes it often fails to connect to qrexec agent at subsequent boot causing the user to be forced to kill the AppVM which causes the machine to fail to connect co qrexec agent which causes a spiral of misery. Here's how to fix that:

1. Disable Seamless GUI and enable debug mode of Windows VM
2. Start Windows VM
3. In the VM window You'll see the Safe Mode prompt. This prompt is the real cause of the issue as the 30 second timer prolongs the boot process which in turns causes qrexec to timeout. Select "Start Windows normally.
4. In Windows AppVM launch Command Prompt as Administrator
5. Use following commands in the Commands Prompt: "bcdedit /set {bootmgr} displaybootmenu no" (no quotes) and "bcdedit /set {default} bootstatuspolicy ignoreallfailures" (no quotes)
6. Shutdown Windows machine
7. (optionally) change how long the qrexec waits for connection from the default 60 seconds to 120 seconds
8. Enable Seamless GUI back and disable debug mode

Your Windows VM should start normally after a crash now.

[Max]

Hi,

Thanks for putting these steps together. I believe I am suffering from the same issue but I can't follow the steps fully. If this is not the same issue, I will delete this and start another thread.

When I try to start my Win 7 VM, it fails to start. If I start it using the Debug mode I get the following error when using safe mode:

"Cannot connect to 'windows-7' qrexec agent for 300 seconds, giving up ERROR: Cannot execute qrexec-daemon!"

Looking at previous similar issues, I have attempted to re download the Windows Tools again but this has not worked.

If I start Windows normally however using the debug option, Windows just hangs at a "Starting Windows" screen and the Dom0 Terminal just shows "Waiting for user 'Max' login..." without progressing.

Any suggestions as to how to troubleshoot this?

Thanks

[Grzesiek Chodzicki]

Enable Debug, Disable Seamless GUI and then mash F8 as soon as the OS window appears, enter either Safe Mode with Networking or Last Known Good Configuration and then do a clean shutdown from within a VM. Helped me several times.

[Max]

Even doing this I can't get in at all and get the same error as described above. Is it going to be required to re install Windows again?

Thanks for taking the time to detail your experiences.

[Grzesiek Chodzicki]

Did you attach any PCI devices to the Windows VM? I've noticed that if a PCI device was attached at any point to a Windows VM and detached afterwards the VM will not boot unless said device is attached again.

[Max]

No, I didn't. I have opted to go for the reinstall from backup route to getting Windows working again (which it is). Thanks anyway for the help.