Re: [libvirt-users] Calling 'virsh' from within a hook script - avoid deadlock?

Michal Privoznik
Thu, 07 Nov 2013 09:16:29 -0000

On 06.11.2013 16:17, Michal Privoznik wrote:
> On 06.11.2013 11:23, TSADOK, Shlomi (Shlomi) wrote:
>> [...]
>
> http://libvirt.org/hooks.html#recursive
>
> Do not do this.
>
> Michal
>

Maybe I should explain a bit why this is not supported. It's true that
libvirt is multithreaded. However, not in terms of multiple write/modify
accesses to a single domain. That is, when a domain is being started up
it is a modify access. Meanwhile, at some point during the transaction
the startup hook script is called. If the script decides to start
another modify transaction an deadlock occurs.

Michal