Re: [libvirt] kvm migration

Łukasz Mierzwa wrote: > 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. Yeah, the persistent flag idea is a good one. I think people would find that useful, and it's fairly easy to implement. I'll give it a shot.