Re: [libvirt] kvm migration

Dnia wtorek 19 maj 2009 o 22:20:06 Daniel P. Berrange napisał(a): > On Tue, May 19, 2009 at 09:29:15PM +0200, ??ukasz Mierzwa wrote: >> Hi, >> >> can someone explain me how migration works in libvirt? I got 2 machines >> with ubuntu 9.04 (libvirt 0.6.1 and kvm 84), disk images are stored on >> nfs share so both machines can access them. When I run live migration >> (virsh migrate --live domain uri) my domain is migrated to second host >> but: >> 1. domain is defined on both hosts after migration, it does not disappear >> from original host >> 2. when I shutdown this domain on second host it gets undefined >> so I guess that migration is only temporary but this is not what I want. >> When I migrate domain to other host I want it to stay there, how can I do >> that? I can't find anything about it in documentation on libvirt website, >> google does not seem to know anything either. > You need to distinguish between a persistent and transient guest. > A persistent guest has a config file, a transient guest does not. > > If the guest on the source host is persistent, then after migration > you should still see it on the source host as inactive. If it is > transient, then all trace should have gone after migration. > > If the destination does not already have a config file for the incoming > guest, then it will become a transient guest. Once you shut it down on > the destination, all trace will go away., If the destination has a config > for the guest it will become persistent, and the guest should still > exist. > > Based on your description I'd say your source host had a persistent guest, > and the destination host did not have a config, so after migration the > guest was transient. > > > Daniel So if I want my guest to be undefined from the source host and stay on target host I need to define him on target host before migration? Some info in 'virsh help migrate' would be nice, and maybe '--persistent' option to auto-define it on target before migration. Thanks for help.