On 23/05/13 20:57, David Vossel wrote: > ----- 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 > David,
Yes we definitely do. https://fedoraproject.org/wiki/Features/Virt_Storage_Migration is being added to Fedora 19, so eventually we will see such support across the board, so some people might want to use it. To quote: New developments in QEMU allow migrating a VM with no shared storage between the source and destination, and does it in a performant manner. So, the issues seem to be getting addressed, at least with kvm/qemu/libvirt. Regards, Tristan -- Tristan Santore BSc MBCS TS4523-RIPE Network and Infrastructure Operations InterNexusConnect Mobile +44-78-55069812 [email protected] Former Thawte Notary (Please note: Thawte has closed its WoT programme down, and I am therefore no longer able to accredit trust) For Fedora related issues, please email me at: [email protected] _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
