On Wed, Jan 2, 2013 at 3:53 AM, Robert Dinse <nanook at eskimo.com> wrote: > > Friday, I moved our servers to a new co-lo facility and ran into an > interesting problem with virtual machines. > > I did an orderly shutdown of the CentOS 6.3 host, and it in turn > suspends > all the guests. It took about an hour and a half to move and fire up the > host. > > By default VMs suspend when the host node is shutdown. You can change this behavior in /etc/sysconfig/libvirt-guests By shutting down the VMs you don't have to wait for the in-memory data to be dumped to disk, nor do you have to wait for it to be copied back from disk and into memory on boot. > The guests, being suspended, were then an hour and a half behind and > it > seems ntpd does not want to correct more than 1000 seconds of error so it > would > not automatically adjust the clocks. > At my place of employment we noticed the same thing during maintenance, the VMs had their clocks all out of whack. > > I tried the -g argument which is supposed to override the 1000 second > limit but it did not. I ended up having to manually set the clocks close > enough for ntpd to correct. > > I believe we had manually correct the clocks as well on ours, but it's been months since then. > Since there is no hardware clock for the virtual machines to use when > they > boot, it seems that shutdown and reboot of the virtual machines probably > would > not have avoided this. > > Any suggestions for addressing this particular scenerio other than > having > to manually set a bunch of clocks? > > > -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_- > Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting. > Knowledgeable human assistance, not telephone trees or script readers. > See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874 > . > > > _______________________________________________ > CentOS-virt mailing list > CentOS-virt at centos.org > http://lists.centos.org/mailman/listinfo/centos-virt > -- ---~~.~~--- Mike // SilverTip257 // -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos-virt/attachments/20130102/bc50776d/attachment-0006.html>