Re: [Libvir] Restarting of libvirt_qemud daemon

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.