Open Stack

Hi all,

I'm experiencing the following problem doing a short term multiple
resize test using XenServer6 as hypervisor.
On first resize everything works as expected. If I do another resize a
few minutes after the first one, I receive an error about VHD coalesce
attempts exceeded on destination host's nova-compute.log:
http://paste.openstack.org/show/3368/

On the hypervisor's /var/log/SMlog I can find errors like this:
http://paste.openstack.org/show/3369/

Can someone give me some advice about this issue?
Is it something related to the hypervisor?  Do I need to wait longer
between a resize an the other?

Thanks a lot
Giuseppe