QubesOS 4.2 freezes (using KVM switch)

User Support
1

Hi there,

I did a fresh (default) installation of QubesOS R4.2.0 on a HPE Z240 (latest BIOS) with Intel Xeon E3-1240v5, 32GB RAM, NVidia Quadro K620 graphics card. Memtest was executed for several days without problems.

I am using a KVM switch (USB and graphics card connection) to switch between 2 computers.

I have the problem that QubesOS freezes after some time. I am working on the other computer and when switching back to QubesOS xfce is freezed. But: I am still able to move the mouse and see the mouse pointer moving. I am unable to click on any window or to enter text.

I am also able to login to cli by pressing Ctrl+Alt+F4. Changing back with Ctrl+Alt+F1 does not change anything.

I did another install and disabled “Use a qube to hold all USB controllers” (sys-usb) - this didn’t change anything, freeze is still there.

I checked the logs in /var/log/xen/console and /var/log/Xorg.0.log, but did not find any cause for the freeze.

Is there anything more I can do/check to find the cause for the freeze?

Best regards,
cyb

2

Are you able to login in TTY and execute the commands there?

3

Hi apparatus,

yes, exactly. When pressing Ctrl+Alt+F4 I am able to login with the user account. I am able to execute commands there (e.g. checking the logs with less).

So the system is not totally freezed. Mouse pointer is moving, Ctrl+Alt+F4 is working. But the gui (xfce?) is not working as it should.

Best regards,
cyb

4

Maybe it’s just a bug with screensaver?
Try to enter the password and hit Enter in the frozen xfce.

2 Likes
5

Ah, excellent hint! You are right, after entering the password and hitting enter, xfce is operable again.

Very strange behaviour indeed.

Best regards,
cyb

6

Possibly a problem with resume from suspend.

7

Have you tried increasing the sys-usb VM memory? I think increasing the memory fixed this issue for me.

1 Like