On 23-12-15 10:45, Daniel P. Berrange wrote:
On Wed, Dec 23, 2015 at 10:29:04AM +0100, Wido den Hollander wrote:
This allows user to use the volume wiping functionality of the libvirt storage driver.
All data from the volume will be wiped by calling rbd_discard() in chunks of the underlying object and stripe size inside Ceph.
This will ensure all data is zeroed and leaves the user with a completely empty volume ready for use again.
Based on the name 'rbd_discard' it sounds like this is going to call TRIM/DISCARD on the underlying storage too ? If so, then I don't think that this is an appropriate approach for this API. The virStorageVolWipe API should clear the data, *without* having any effect on the storage of the API - ie we don't want to discard underling storage blocks as a side effect
Afaik it zeroes/trims all the RBD objects on the Ceph cluster, but it doesn't TRIM the lower SSD on it's turn. So it will send these calls to Ceph/RBD and it will zero all the data of that specific volume. A rather simple way to get rid of the data in a volume. If makes sure that the volume no longer contains any data for the end-user. All user-data on the volume will be gone. Or am I misunderstanding you? What is it supposed to do? Wido
Regards, Daniel