[libvirt] timing issues of calling virsh on the command line

[Daniel Veillard]

On Sat, Nov 07, 2009 at 10:24:30AM -0500, David Wilcox wrote:
> Hi,
> 
> I've encountered some concurrency issues when calling virsh in a script. If
> I try to restore a VM too soon after it's been saved, libvirtd will stop
> responding. As well, if I try to save a VM too soon after it's been
> restored, libvirtd will stop responding.

  First what version are you using ? What kind of domains, what versions
of the hypervisor etc ...

Second assuming something recent, could you run /usr/sbin/libvirtd under
gdb, then reproduce the problem and provide a stack trace ? See the end
of
  https://fedoraproject.org/wiki/How_to_debug_Libvirt_problems

  for detailed informations
If libvirtd is not responding it's very probably crashed, and we need to
fix the crash.

> At the moment, I am not using any type of wait in my program for virsh to
> come back. I merely let the system call run its course and I assume that
> virsh will return when it's done waiting.
> 
> Is there any type of wait that needs to occur in order to avoid these
> concurrency issues?

  The operation should be synchronous, so no wait should be needed
  something is behaving.

Daniel

-- 
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