On Thu, Jun 11, 2015 at 07:28:10PM +0200, Dominique Ramaekers wrote:
Hi,
I'm experimenting with the migration function of virsh. I'm doing the
migrate with following commands:
virsh migrate --life --persistent --copy-storage-all --verbose
--abort-on-error domain qemu+ssh://root@destination/system virsh
migrate-setmaxdowntime domain 20000
However sometimes at the end of the migration, the guest isn't started
on the destination host. So I'm left with a machine that had an
improper shutdown...
If a live migration isn't reliable, I'm thinking to migrate as such: -
guest is still runing - copy or rsync the disk image to the
destination - shut down the guest - rsync the disk image again (to
minimise the off-line period) - dumpxml of guest and copy to
destination - define and start the guest on the destination
With the methode of the live migration, the machine will be
unresponsive for max 20s = 20000ms (or less if I chose to). The
migration it self will take op to 5 hours but I guess I plan these
nightly.
With the other migration the guest will be really off-line for the
duration of the (second) rsync. In my case with disk images from 50 to
150Gb, the rsync wil take up at least 30 minutes and every connection
will be closed...
Does any body has good experiences with live migrations (without
shared storage)? Any tips?
Any thoughts on the second method of migrating?
While no immediate answer on why your guest on destination host doesn't
start, but I've previously successfully tested wih qemu+tcp URI and
these three variants, without shared storage:
(1) Native migration, client to two libvirtd servers
$ virsh migrate --verbose --copy-storage-all \
--live cvm1 qemu+tcp://kashyapc@desthost/system
(2) Native migration, peer2peer between two libvirtd servers:
$ virsh migrate --verbose --copy-storage-all \
--p2p --live cvm1 qemu+tcp://kashyapc@desthost/system
(3) Tunnelled migration, peer2peer between two libvirtd servers:
$ virsh migrate --verbose --copy-storage-all \
--p2p --tunnelled --live cvm1 qemu+tcp://kashyapc@desthost/system
Related notes here:
https://bugzilla.redhat.com/show_bug.cgi?id=1202453#c19
--
/kashyap