[Libvir] Restarting of libvirt_qemud daemon
Richard W.M. Jones
rjones at redhat.com
Fri Mar 9 13:55:16 UTC 2007
Daniel P. Berrange wrote:
> On Fri, Mar 09, 2007 at 10:47:18AM +0000, Richard W.M. Jones wrote:
>> Daniel P. Berrange wrote:
>>> Thinking about later RPM upgrades I think we need to think about whether it
>>> will be possible to restart the libvirt_qemud while guests & networks are
>>> running. There's a couple of issues:
>>>
>>> - We do waitpid() to cleanup qemu & dnsmasq processes when we stop domains
>>> & networks, or to detect when they crash. For the former, we could may
>>> they daemons to avoid waitpid() cleanup, but we'd still need waitpid to
>>> be able to detect shutdowns. There is also the issue of enumerating
>>> running instances.
>> Maybe I'm missing something big here, but how would libvirt_qemud regain
>> connections to the running qemu monitor ptys?
>
> That's one of the challenges to be addressed :-) Fortunately the monitor
> is set to be exposed via /dev/pty/XXX, so if the restarted client can
> find out the path to the PTY, then it can re-open it. Maybe we just need
> to record a state file somewhere containing a PID & PTY path.
Is it possible to start qemu with something like:
qemu -monitor pipe:/var/some/known/place/pipe.UUID
and then just look in /var/some/known/place/ in order to find the
running instances?
Rich.
--
Emerging Technologies, Red Hat http://et.redhat.com/~rjones/
64 Baker Street, London, W1U 7DF Mobile: +44 7866 314 421
"[Negative numbers] darken the very whole doctrines of the equations
and make dark of the things which are in their nature excessively
obvious and simple" (Francis Maseres FRS, mathematician, 1759)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 3237 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20070309/0a6a1b1f/attachment-0001.bin>
More information about the libvir-list
mailing list