Open Stack

On 11/03/2013 08:39 PM, Qixiaozhen wrote:

> In my opinion, we should rethink the way of wiping the data in the
> volumes. Filling in the device with /dev/zero with “dd” command was the
> most primitive method.  The standard scsi command “write same” could be
> taken into considered.
>
> Once the LBA was provided and the command was sent to the SAN , the
> storage device(SAN) could write the same-data into the LUN or volumes.
> The “dd” operation  can be offloaded to the storage array to execute.

This will offload the CPU on the compute nodes, but it still uses disk I/O.

Personally I like the elegance of giving each user a certain amount of 
I/O and giving them the option of unsecure or secure deletion.  If they 
choose the secure deletion then that disk bandwidth comes out of their 
quota and the volume size is still billed against them until it is done 
being deleted.

By asking for the secure deletion they are essentially still making use 
of those resources until the deletion is complete, so I think it's fair 
that it count towards their quota/usage stats.

Chris