Re: [libvirt] [PATCH] 514532 Fix man page, most operation are synchronous

On Thu, Nov 19, 2009 at 04:34:12PM +0000, Daniel P. Berrange wrote: > On Wed, Nov 18, 2009 at 02:31:12PM +0100, Daniel Veillard wrote: > > > > -Most B<virsh> commands act asynchronously, so just because the B<virsh> > > -program returned, doesn't mean the action is complete. This is > > -important, as many operations on domains, like create and shutdown, > > -can take considerable time (30 seconds or more) to bring the machine > > -into a fully compliant state. If you want to know when one of these > > -actions has finished you must poll through virsh list periodically. > > +Most B<virsh> commands act synchronously, except maybe shutdown > > +and domain creation. In those case the fact that the B<virsh> > > +program returned, may not mean the action is complete and you > > +must poll through virsh list periodically to detect that the > > +operation completed. > > Shutdown is async, but domain creation is certainly supposed to > be synchronous. Of course the guest may immediately crash > so appear inactive again just after create returns Well I was also thinking that Create like Shutdown, the process is at best started in the Domain OS but completion can't be asserted just because the command started. I think the idea of creating the guess is also implicitely tied with the OS booting th the mind of users, and well their domain won't respond to requests for a little bit even if the create succeeded. > Thinking about it, I believe virDomainShutdown/Reboot, and the SetMemory > and SetVcpus are the only two APIs that are allowed to be async, because > they merely update the guest, but don't wait for it to react.