[pve-devel] [PATCH kernel] Backport two io-wq fixes relevant for io_uring

[Mark Schouten]

Hi,

Ok. Funny enough, I suffered from this issue last night during maintenance… But since I have not had this issue before, I had no snapshot…

I guess the snapshot would need to have a state as well, right? So the machine is ‘booted’ as it was.

— 
Mark Schouten, CTO
Tuxis B.V.
mark at tuxis.nl



> On 9 Mar 2022, at 08:31, Fabian Ebner <f.ebner at proxmox.com> wrote:
> 
> Am 08.03.22 um 17:19 schrieb Mark Schouten:
>> Hi,
>> 
>> So should I try and find someone who is able to reproduce this with a test-machine and is able to give you remote access to debug? Would that help?
>> 
> 
> It would certainly increase the likelihood of finding the issue. Since
> it only happens on 7.x, it's likely a regression. Ideally, there needs
> to be a snapshot of a problematic VM before the reboot, so that it can
> be quickly tested against with e.g. different builds of QEMU/kernel.
> Providing such a VM with snapshot state would of course be an
> alternative to remote access.
> 
>> — 
>> Mark Schouten, CTO
>> Tuxis B.V.
>> mark at tuxis.nl
>> 
>> 
>> 
>>> On 8 Mar 2022, at 10:12, Fabian Ebner <f.ebner at proxmox.com> wrote:
>>> 
>>> Am 07.03.22 um 15:51 schrieb Mark Schouten:
>>>> Hi,
>>>> 
>>>> Sorry for getting back on this thread after a few months, but is the Windows-case mentioned here the case that is discussed in this forum-thread:
>>>> https://forum.proxmox.com/threads/windows-vms-stuck-on-boot-after-proxmox-upgrade-to-7-0.100744/page-3 <https://forum.proxmox.com/threads/windows-vms-stuck-on-boot-after-proxmox-upgrade-to-7-0.100744/page-3>
>>>> 
>>>> ?
>>> 
>>> Hi,
>>> the symptoms there sound rather different. The issue addressed by this
>>> patch was about a QEMU process getting completely stuck on I/O while the
>>> VM was live already. "completely" meant that e.g. connecting for the
>>> display also would fail and there would be messages like
>>> 
>>> VM 182 qmp command failed - VM 182 qmp command 'query-proxmox-support'
>>> failed - unable to connect to VM 182 qmp socket - timeout after 31 retries
>>> 
>>> in the syslog. The issue described in the forum thread reads like it
>>> happens only upon reboot from inside the guest and nobody mentioned
>>> messages like the above.
>>> 
>>>> 
>>>> If so, should this be investigated further or are there other issues? I have personally not had the issue mentioned in the forum, but quite a few people seem to be suffering from issues with Windows VMs, which is currently holding us back from upgrading from 6.x to 7.x on a whole bunch of customer clusters.
>>> 
>>> I also haven't seen the issue myself yet and haven't heard from any
>>> colleagues either. Without a reproducer, it's very difficult to debug.
>>> 
>>>> 
>>>> Thanks,
>>>> 
>>>> — 
>>>> Mark Schouten, CTO
>>>> Tuxis B.V.
>>>> mark at tuxis.nl
>>> 
>> 
>> 
>> 
>