VM goes unresponsive though QEMU remains responsive

English Virtualization
1

I’m Leap 16.0 (just upgraded) but problem occasioned in 15.6.
Got loads of memory in (OpenSuSE 16.0) VM, even though often lots of windows open and lots of tabs in Firefox,

Blockquote
$ free

shows lots of memory available.
BUT the VM is unresponsive. Clicking on other windows or <.ALT><.TAB> doesn’t to anywhere.
The mouse pointer is still visible. I can <.LeaveFullScreen> and see particulars in the Virtual Machine Monitor GUI, and can switch to my Ubuntu VM and do something.

But the OpenSuSE VM is dead to me.
I access the top menu, which is responsive, and choose

Blockquote
Virtual Machine | shutdown | force reset

Reboots and generally recover to approximately where and what I was doing.

Where do go to start debugging what is my problem?

2

You probably did run free on the host system, true?

If so this does not say anything about the memory allocated to the VM. Check those settings

3

No. Run on VM only.

$ free -h
total used free shared buff/cache available
Mem: 15Gi 12Gi 264Mi 274Mi 3.0Gi 2.6Gi
Swap: 2.0Gi 676Mi 1.3Gi

If it matters, my host is 64Gi.

df shows my VM is 42% used wtih 86GiB available.
My host is 4TiB using software RAID so it’s presumed 2TiB

4

I think it is good to first to determine whether:

  • only the GUI session froze, or
  • the whole guest OS froze.

When such a hang occurs:

  • Try switching to a text console: Ctrl + Alt + F3 through F6
  • If it does not work, try to SSH into the guest to see if networking is still up
  • systemctl status qemu-guest-agent (on the host)

Also, study the log of the previous boot that did hang using “journalctl -b -1”. You can share that using susepaste.

5

It’s only the OpenSuse guest that freezes.
I can get to the top and see the virtual machine manager–as well as do things.
VM in question is quiescent.

And can switch to my UBUNTU guest.

Can get the openSuse guest that won’t respond, but the top-level menu, I choose “Virtual Machine” and force a restart, and essentially pick up where I left off.

$ sudo journalctl -b -1
Specifying boot ID or boot offset has no effect, no persistent journal was found.

But the next time my guest freezes, I’ll try to do this.
Thanks for the counsel and advice.

6

If it matters, when I’m frozen, that is, no response to mouse-click nor <.alt><.tab>, things like my VLC playing internet radio continues unabated.
And the mouse obviously is moving about, as I can get back to my hypervisor, switch to another guest, etc.

^<.alt><.F3> gets my to my host terminal, I shared those results earlier – nothing!

When I click that <.leaveFullScreen> at the top of the screen to get to the virtual machine window, I can <.sendKey> and click send ^<.alt><.F3>, to try to get to my VM to do that journalctl from it instead of my host, nothing happens and it doesn’t change my situation.

This last time, after it came back from my <.virtualMachine | shutdown | forceReset> I immediately did the sudo journalctl -b -1 you requested, it showed the same nothing as before.

If it’s of any interest, when it comes back, sound no longer works. I must do a shutdown/reboot from my terminal to get fully back.

Thanks for all the help, guys; sorry if my terminology isn’t always up to snuff, and responses aren’t always the most timely as I’m away from my computer often.

7

@suseParsons What do the logs on the host say about the virtual machine?

What desktop environment is on the Client (Leap 16.0), what filesystem?

8

Both are BTRFS
Both are Leap 16.0
Both are Gnome.

forgive my ignorance:
On host, which logs do you wish me to inspect? And looking for what ?

9

@suseParsons just tail the host log when the vm is running journalctl -f to see is any output related when the vm freezes. Are you using QXL for the graphics on the vm?