----- Original Message ----- > From: "Greg Woods" <[email protected]> > To: "General Linux-HA mailing list" <[email protected]> > Sent: Thursday, May 23, 2013 2:45:16 PM > Subject: Re: [Linux-HA] vm live migration without shared storage > > On Thu, 2013-05-23 at 15:00 -0400, David Vossel wrote: > > Migration time, depending on network speed and hardware, is much longer > > than the shared storage option (minutes vs. seconds). > > > This is just one data point (of course), but for the vast majority of > services that I run, if the live migration time is as long as it takes > to shut down a VM and boot it on another server, then there isn't much > of an advantage to doing the live migration. Especially if we're talking > about an option that is a long way from being battle-tested, and > critical services such as DNS and authentication. Most of these critical > services do not use long-lived connections. > > I can see a few VMs that exist to provide ssh logins where a > minutes-long live migration would be clearly preferable to a shut down > and reboot, but in most cases, if it's as slow as rebooting, it isn't > going to be any advantage to me. > > It will be interesting though to see how many applications people come > up with where a minutes-long live migration is preferable to shutdown > and reboot.
The actual migration takes awhile, but the transition between running on the source and running on the destination should be very fast. The source stays running while the disk is being copied to the destination, once the copy is complete it's like flipping a switch... at least that's my understanding. -- Vossel > > --Greg > > > _______________________________________________ > Linux-HA mailing list > [email protected] > http://lists.linux-ha.org/mailman/listinfo/linux-ha > See also: http://linux-ha.org/ReportingProblems > _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
