On 24/05/13 09:03, Tristan Santore wrote: > On 23/05/13 20:57, David Vossel wrote: >> ----- Original Message ----- >>> From: "Greg Woods" <wo...@ucar.edu> >>> To: "General Linux-HA mailing list" <linux-ha@lists.linux-ha.org> >>> 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 >>> Linux-HA@lists.linux-ha.org >>> http://lists.linux-ha.org/mailman/listinfo/linux-ha >>> See also: http://linux-ha.org/ReportingProblems >>> >> _______________________________________________ >> Linux-HA mailing list >> Linux-HA@lists.linux-ha.org >> 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 > Sorry, I meant to address this to Greg! After checking David's post, I realised he made the same point as I did. Sorry David.
Regards, Tristan -- Tristan Santore BSc MBCS TS4523-RIPE Network and Infrastructure Operations InterNexusConnect Mobile +44-78-55069812 tristan.sant...@internexusconnect.net 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: tsant...@fedoraproject.org _______________________________________________ Linux-HA mailing list Linux-HA@lists.linux-ha.org http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
