Re: Error checking on migration?

[Anthony Liguori <aliguori@us.ibm.com>]

John Byrne wrote:
>
> I've noticed that migration doesn't fail if the VM cannot access the 
> disk image on the new host. (xen-unstable 10273)  The VM ends up on 
> the new host and hangs when it does a disk access. This is a somewhat 
> evil behavior.

You could add some basic sanity checking in XendRestore.py:restore() 
before xd.restore_() is invoked.  A consequence of doing device setup 
through scripts is that the only proper way to know if a device creation 
will succeed is by actually creating it.  It's further complicated by 
the race condition that results by doing the checking before actually 
grabbing the devices (what if another migration is in progress that 
happens to use the same devices).

At any rate, having some sort of error checking is probably better than 
having none at all.

Regards,

Anthony Liguori

>
> Does anyone have a fix for this in-hand, somewhere? If not, any advice 
> where to look to fix the problem?
>
> Thanks,
>
> John Byrne
>
>
>
>
>
>
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