[CentOS-virt] VirtIO disk 'leakage' across guests?

Mon Jan 16 21:51:47 UTC 2012
Dennis Jacobfeuerborn <dennisml at conversis.de>

On 01/16/2012 07:05 PM, James B. Byrne wrote:
> We are in the process of migrating several stand-alone
> server hosts onto a CentOS-6 kvm virtual host.  We also
> use Webmin to administer our hosts.  All of the guests,
> without exception, have been cloned brom a prototype guest
> using virt-manager.  All of the additional VirtIO disks
> assigned to some of the guests have been added through
> virt-manager as well.
> Recently I have encountered a situation with the
> development copy of Webmin where I can see an additional
> VirtIO disk assigned to one guest instance, but not yet
> added to the lvg of that guest, as an unknown device on
> different guest.  Further, I can see an lv assigned to one
> guest instance as an lv on a difference guest.
> The webmin author is aware of this problem and is
> assiduously trying to determine its cause.  My difficulty
> is answering the question: How is it even possible for an
> application running under a httpd service on one guest to
> see anything at all besides the VirtIO storage assigned to
> that guest?
> Has anyone else encountered this anomaly?

Can you share the (vg|lv|pv)display on two such guests that allegedly share 
a disk? A dumpxml and lvdisplay of the host side of there two guests would 
be useful too.
The only case where I have seen stuff like this was when someone was using 
unpartitioned virtual disks as physical volumes in the guests which 
resulted in the host picking up the metadata and "discovering" the vg/lv/pv 
data of the guests on the host side. What a mess that was.