Re: I/O errors after migration - why?

[Anthony Liguori <anthony@codemonkey.ws>]

Tomasz Chmielewski wrote:
> Tomasz Chmielewski schrieb:
>> Tomasz Chmielewski schrieb:
>>> Tomasz Chmielewski schrieb:
>>>> I'm trying to perform live migration by following the instructions 
>>>> on http://www.linux-kvm.org/page/Migration.
>>>> Unfortunately, it doesn't work very well - guest is migrated, but 
>>>> looses access to its disk.
>>>>
>>>> On the destination host, I'm starting the guest with exactly the 
>>>> same options as on the source host, with "-incoming tcp:0:4444".
>>>> On the source host, I start the migration with "migrate -d 
>>>> tcp:B:4444".
>>>>
>>>> Both hosts use the same iSCSI device and can access it.
>>>>
>>>> Looks like the destination host can't really access the iSCSI 
>>>> device after all? No - after I reboot the guest (echo b > 
>>>> /proc/sysrq-trigger), it boots just fine from its disk. Also lsof 
>>>> on the host shows that the kvm process accesses the correct 
>>>> /dev/sdX device.
>>>
>>> Similar symptoms with virtio_blk (i.e., when guest is booted off a 
>>> live CD and tries to access the disk after migration).
>>>
>>> The only difference between SCSI and virtio_blk is that SCSI signals 
>>> errors and aborts, and virtio_blk waits forever and doesn't give a 
>>> clue.
>
> That is interesting (or not?).
>
> In monitor, after migration, "info block" says:
>
> scsi0-hd0: type=hd ...
>
> Before migration, it was:
>
> virtio0: type=hd ...
>
> ?
>
> On both sides the guest was started with the same option (delta 
> "-incoming...").

Can you give the full command line on both ends and what KVM version it is?

Regards,

Anthony Liguori