----- Original Message ----- > From: "Shahar Havivi" <shah...@redhat.com> > To: "Alon Bar-Lev" <alo...@redhat.com> > Cc: vdsm-devel@lists.fedorahosted.org > Sent: Monday, April 6, 2015 2:54:07 PM > Subject: Re: [vdsm] vdsm hosts clock sync > > On 06.04.15 07:50, Alon Bar-Lev wrote: > > > > > > ----- Original Message ----- > > > From: "Shahar Havivi" <shah...@redhat.com> > > > To: vdsm-devel@lists.fedorahosted.org > > > Sent: Monday, April 6, 2015 2:44:06 PM > > > Subject: [vdsm] vdsm hosts clock sync > > > > > > Hi, > > > > > > I want to add a new feature that reports migration actual downtime (the > > > time > > > that the VM was inaccessible to the user). > > > > > > Libvirt reports that information but the vdsm hosts need to be in sync by > > > clock > > > time. > > > I can measure the ping for NTP server an report back to the user if the > > > ping > > > is too long (more then ~100ms or so) - a way to do that is via ntpstat > > > shell > > > command. > > > The NTP delay can be report back via vdsStats and can be performed every > > > few hours or so. > > > > > > Anyone knows of a better way that we can sync between hosts? > > > > I am unsure how a ping to clock source is helping, can you please explain > > more? > In this case I can only report back to the user that its hosts clock is > delayed and need to be set... > > > > If you assume clocks are synced why anything more is needed? > Why do I assume that? > > > > Or would you like to have a solution in which you do not require clock > > sync? > > I do need the clock to be in sync - if not libvirts "actual downtime > migration" will be not accurate.
you do not need clock to sync, you need to know the delta between hosts. but if you assume clock are in sync so what is the actual question? > > > > > > > > > Thank you, > > > Shahar Havivi. > > > _______________________________________________ > > > vdsm-devel mailing list > > > vdsm-devel@lists.fedorahosted.org > > > https://lists.fedorahosted.org/mailman/listinfo/vdsm-devel > > > > _______________________________________________ vdsm-devel mailing list vdsm-devel@lists.fedorahosted.org https://lists.fedorahosted.org/mailman/listinfo/vdsm-devel
