[libvirt] strange stale qemu processes after domain shutdown

[Michal Privoznik]

On 15.10.2015 20:41, Vasiliy Tolstov wrote:
> I have 58 active domains with status running, and 62
> qemu-system-x86_64 processes.
> After investigating this issue, i found problem domains.
> How to fix this issue and not lost this qemu processes?

These are probably left over after daemon restart. I mean, when deamon
restarts, it reloads the state XML. However, if there's something wrong
(e.g. unknown device), the state XML is ignored and libvirt thinks the
domain is shut off, leaving qemu process behind. The unknown device can
happen if you run older daemon than the domain has been started with.

You can check daemon debug logs and see how it loads domain state XMLs.
If there's an error somewhere it's possibly this case.

Of course, the other option would be that we have a bug somewhere where
we leave qemu process behind. But the former is more likely than the latter.

Michal