Re: [libvirt] Block-migrate
Hi Daniel,
On Wed, Aug 11, 2010 at 14:16, Daniel P. Berrange <berrange(a)redhat.com> wrote:
On Sat, Aug 07, 2010 at 03:55:10PM +0200, Ruben Kerkhof wrote:
> I've been playing with the new block-migrate feature, but am unable to
> get it to work.
>
> [root@src ~]# virsh migrate --live --p2p --tunnelled
> --copy-storage-all 4c5c75b9-decc-41c9-9296-20ca5bd5c355
> qemu://dst/system
> error: Unknown failure
>
> /var/log/libvirt/qemu/4c5c75b9-decc-41c9-9296-20ca5bd5c355.log on the
> destination host shows:
>
>
bind(unix:/var/run/libvirt/qemu/qemu.tunnelmigrate.dest.4c5c75b9-decc-41c9-9296-20ca5bd5c355):
> Permission denied
> Migration failed. Exit code
>
unix:/var/run/libvirt/qemu/qemu.tunnelmigrate.dest.4c5c75b9-decc-41c9-9296-20ca5bd5c355(-22),
> exiting
>
> It seems that qemu is not able to write to that location.
>
> [root@dst qemu]# ls -ld /var/run/libvirt/qemu/
> drwx------. 2 root root 4096 Aug 7 15:40 /var/run/libvirt/qemu/
>
> As a workaround I gave qemu write permission, and now the block migrate starts.
Did the disk image files exist on the target before migration started ?
If not, then this is going to be falling foul of our security drivers
which prevent QEMU creating new files itself.
I'm working with raw lvs and created them on the destination before
starting the migration.
Also, a straw poll of people at the KVM forum yesterday determined
that no
one had ever got block migration to work, so it might be just broken in
QEMU
Daniel
Actually, I've got it working now, with the --direct option and the
--p2p --direct option.
The tunneled method fails though. I'm trying to debug this now.
The first thing which strikes me as odd is in the
qemuMonitorTextMigrate function:
1173 if (qemuMonitorCommand(mon, cmd, &info) < 0) {
(gdb) p cmd
$4 = 0x7fffdc0e6ef0 "migrate -d
-b\"unix:/var/run/libvirt/qemu/qemu.tunnelmigrate.src.4c5c75b9-decc-41c9-9296-20ca5bd5c355\""
(gdb) n
1180 if (strstr(info, "fail") != NULL) {
(gdb) n
1181 qemuReportError(VIR_ERR_OPERATION_FAILED,
(gdb) p info
$5 = 0x7fffe8001210 "migration failed\r\n"
Not sure if there's supposed to be a space between the migrate and the
-d option, and no space after the -b.
Regards,
Ruben