[libvirt-users] vol-wipe and delete
Hello all, I know libvirt has the following two commands: vol-wipe vol-delete Can someone please explain to me how these function? Do these only remove previous session data so that a new virtual instance cannot see it or does it remove it at the physical level level too so that the data cannot be found anywhere on the physical drive? I know Eucalyptus and KVM use sparse files upon instance creation and the instance thinks the ephemeral space is all zeroes even though it is just sparse. I appreciate any insight in how the two virsh commands work and if they use zeroes, sparse, or some other method. Thanks, Shawn
On 04/10/2012 06:20 PM, Shawn Davis wrote:
Hello all,
I know libvirt has the following two commands:
vol-wipe
calls virStorageVolWipe or virStorageVolWipePattern (depending on arguments), which overwrites the existing data with all 0 or with a specific pattern. The file stays intact, but future uses of the file will no longer see the data that had been there previously.
vol-delete
calls virStorageVolDelete, which removes the file but does not wipe it (so the data is still present on the backing storage device).
Can someone please explain to me how these function? Do these only remove previous session data so that a new virtual instance cannot see it or does it remove it at the physical level level too so that the data cannot be found anywhere on the physical drive?
If you want the data removed at the physical layer, use vol-wipe. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
participants (2)
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Eric Blake -
Shawn Davis