On Mon, Dec 15, 2008 at 02:51:56PM +0000, Richard W.M. Jones wrote:

I just want to forward this comment on from #virt so that we don't lose it. It appears to be an incompatibility between libvirt 0.5.0 and recent KVM.

<knowinters> Hi, I'm using libvirt 0.5.0 with kvm-79, when I do virsh save kvm replies with "unknown migration protocol: stdio". A state file is created, but it's only 4K and when restored the vm boots from scratch instead of starting where it was when i saved. I googled but couldn't find a resolution. Is this a known issue? <knowinters> nm i think i see what's happening.. it <knowinters> 's using the exec: migration method to call dd to move the state from stdio to a file <knowinters> exec: isn't in kvm-79 i don't think, but i see it in git so ill try that

Suport for the 'stdio' protocol was dropped when migration stuff was merged upto QEMU :-( We should never implemented this in libvirt until it was in QEMU in the first place - we always get screwed when this kind of stuff eventually gets un-forked() into the main codebase. danpb_ltop: aliguori: any idea what happened to '-incoming stdio' migration support.... seems to have disappeared aliguori: danpb_ltop, no particular reason, just requires a patch aliguori: danpb_ltop, what are you using it for? danpb_ltop: libvirt was using it to restore from a saved state image aliguori: danpb_ltop, maybe higher level commands would be better than playing tricks with migration? aliguori: danpb_ltop, i'm happen to take a suspend command that uses live migration to save to an image or something like that danpb_ltop: aliguori: i don't particularly mind - we used to have higher level commands, but they got removed in 0.9.0 :-( danpb_ltop: ok, i'll try and get someone to send a patch for this So another item for the KVM todo list. Implement a 'suspend filename' command in the monitor, and a '-restore filename' command line argument. Or re-add the '-incoming stdio' command line support Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|