Re: pv guests die after failed migration

[Ian Campbell <Ian.Campbell@citrix.com>]

On Tue, 2011-09-20 at 10:42 +0100, Andreas Olsowski wrote:
> When xm failed to do a live migration the system was resumed on the 
> sending host.
> Xl does not do that it TRIES to, but just crashes the guest:
> kernel BUG at drivers/xen/events.c:1466!
> (In this example the target host didnt have the logical volume activated.)
> 
> Now that cant be right.

No, it's a bug, perhaps in the kernel but likely in the toolstack.

Please can you provide full logs from /var/log/xen on both ends. Running
"xl -vvv migrate" will also produce more stuff on stdout, some of which
may be useful.

Also please capture the complete guest log in case it is an issue there.

> Imho xl should do some checking if the target is a viable migration 
> target (are the disks and vifs there, is there enough memory available) 
> and preserve a safe state on the sender until the guest has properly 
> started on the receiver.

xl does have some checks and does preserve the sender side until it gets
confirmation of correct restart, but obviously something is wrong with
the bit which restarts the old guest. I'm sure it worked at one point
though.

Thanks,
Ian.