Em 09-02-2012 20:59, Eric Blake escreveu:
On 02/09/2012 07:00 AM, Nuno Sousa wrote:
Hi all,
Hi have one computer hosting several VM, this particular server is in
need of maintenance and has to be shutdown.
In order to avoid disrupting the services provided by the VM I intended
to migrate the VM to another computer.
Computer 1 and 2 do not share any storage. So it is necessary to migrate
not only the memory but also any data on the hard-drive.
Both computers are running debian squeeze.
Virsh is version 0.8.3.
I issue this command on server one:
sudo LIBVIRT_DEBUG=1 virsh migrate --live --copy-storage-all i00cn1011
qemu+ssh://user@computer2/session> debug.log 2>&1
Based on IRC conversations, I'm assuming you already made sure that
computer2 already sees all the same disk image files, with the same
sizes, as are present on computer1 (the contents need not be identical,
since that is what --copy-storage-all is supposed to fix, but libvirt
currently does not pre-create the files on the destination and leaves
the user to do so instead - patches to fix that are welcome).
Well, are you saying I should copy the data from computer1 to computer2
before using virsh migrate?
I only created an identical LVM partition with the same name and path.
I did not copy anything.
On virt-manager on computer 1, the VM appears for a few moments as
paused, and then disappears.
On computer 1 I receive the error: Timed out during operation: cannot
acquire state change lock
You said virsh 0.8.3 on the source, but I'd also like to make sure what
version of libvirtd is running on the two machines? There are some
known bugs in older libvirt versions where we had bad locking calls; and
some of these bugs could be triggered by migration, such as if
virt-manager is querying domain status at the same time that migration
shuts down the source because the destination is ready to run.7
I have exactly the same version for all packages on both computers.
You may want to upgrade to 0.9.9 (stable release) or 0.9.10-rc2 (release
candidate for next week's release) on both machines, to try and get bugs
that have been fixed in the meantime out of your way. You can safely
upgrade libvirt even while your VM continues to run.
Are you sure there is no problem in me upgrading libvirt on the main
computer?
If so I'll give it a try.
Does anyone know what the problem may be and how to solve it?
At any rate, when older libvirtd hits the 'cannot acquire state change
lock' bug, the only solution is to restart libvirtd (again, a safe
operation; your guest will continue to run in the meantime).
You mean I should restart libvirtd on both computers?
I personally haven't played with --copy-storage-all, and know that it
doesn't get tested quite as much as shared storage, so I hope you can
get things working.
I'll try. And with help I believe I can do it.
Thanks for the help.
