On Tue, Jan 26, 2010 at 11:57:25AM +0200, Kenneth Nagin wrote: > > On January 5 I asked for comments on adding libvirt support for live > migration with non-shared storage on kvm. I did not get any comments so I > am repeating my request: Sorry I missed your original mail - January 5th was unlucky timing, since I had a backlog of several thousand emails from the xmas break :-) > Support for live migration between hosts that do not share storage was > added to qemu-kvm release 0.12.1. > It supports two flags: > -b migration without shared storage with full disk copy > -i migration without shared storage with incremental copy (same base image > shared between source and destination). Interesting, I'd not seen those flags before. How does that work with the destination side, if the disks do not already exist there ? Does the mgmt app have to just create a zero-sized disk, start QEMU & then let the data be copied. I'm guessing QEMU can't create the disk itself, since it'll be trying to open it on the destination before the incoming migration even starts. > I suggest adding these flags to virDomainMigrate. That sounds reasonable. > If I'm not mistaken qemuMonitorTextMigrate is the function that actually > invokes the kvm monitor. > Thus, it would be necessary to pass the flags to qemuMonitorTextMigrate.. > But qemuMonitorTextMigrate does not have a flag input parameter. I think > the least disruptive way to support the new flags is use the existing > "background" parameter > to pass the flags. Of course this would require some changes to the > upstream functions that are invoked for migration. That is an internal function, so adding extra parameters to it is no problem at all - no need to reuse/abuse existing parameters. 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 :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list