Problems with iothread=1 in 6.0-11

[Jan Schreiber]

Hi,

since we migrated to Promox 6.0-11 we're experiencing problems when using iothread=1:

VMs completely freeze when resizing a disk while VM is running (VM is frozen, console is immediately dead)

After doing some research we came to the conclusion that this my be related to this already known bug in QEMU:

https://bugzilla.redhat.com/show_bug.cgi?id=1716316

Is anbody else experiecing this issue? Is there a known workaround?

This might be already fixed in QEMU 4.1 (changelog lists multiple fixes to iothread), are there any plans to upgrade QEMU in Promox in the not so distant future? ;-)

Thank you and kind regards

Jan

 

[t.lamprecht]

This might be already fixed in QEMU 4.1 (changelog lists multiple fixes to iothread), are there any plans to upgrade QEMU in Promox in the not so distant future? ;-)

Yes. There are plans to release 4.1.1 to pvetest repository next week, if internal test do not show issues.

 

[t.lamprecht]

But from your bug report:

upstream v4.1.0-rc4 also hit this issue

and https://wiki.qemu.org/Planning/4.1#Fixed_in_rc5 doesn't says anything regarding, and the 4.1.1 commits are not really mentioning hangs/iothreads either, so not to sure..

since we migrated to Promox 6.0-11 we're experiencing problems when using iothread=1:

what was the previous version, where it worked?

 

[Stefan_R]

I was able to reproduce the issue locally and have opened a bug report for you: https://bugzilla.proxmox.com/show_bug.cgi?id=2486

A fix is indeed available for QEMU, but was not included in the 4.1.1 release we are planning to ship. As mentioned in the bugreport I sent a patch to include it in pve-qemu-kvm.

 

[Jan Schreiber]

Previous version where it worked is 5.3 and 5.4. I'm really glad you've been able to reproduce the issue and thanks a lot for opening a bug report.

 

[Stefan_R]

pve-qemu-kvm version 4.1.1-2 is now available in pve-no-subscription and contains the upstream fix mentioned in the RedHat bug report you linked. Testing appreciated

 

[Jan Schreiber]

Hi,

deployed the new version on one of our nodes and tested, yes it's fixed now.

Thanks a lot, aweseome support!

Kind regards

Jan