Re: Speed up 'rbd rm'

[Chris Dunlop <chris@onthe.net.au>]

On Thu, May 30, 2013 at 01:50:14PM -0700, Josh Durgin wrote:
> On 05/29/2013 07:23 PM, Chris Dunlop wrote:
>> On Wed, May 29, 2013 at 12:21:07PM -0700, Josh Durgin wrote:
>>> On 05/28/2013 10:59 PM, Chris Dunlop wrote:
>>>> I see there's a new commit to speed up an 'rbd rm':
>>>>
>>>> http://tracker.ceph.com/projects/ceph/repository/revisions/40956410169709c32a282d9b872cb5f618a48926
>>>>
>>>> Is it safe to cherry-pick this commit on top of 0.56.6 (or, if not, v0.61.2) to speed up the remove?
>>>
>>> You'll need 537386d906b8c0e395433461dcb03a82eb33f34f as well. It should
>>> apply cleanly to 0.61.2, and probably 0.56.6 too.
>>
>> Thanks. I'll see how I go, I may just leave the 'rm' running all
>> weekend rather than futzing around recompiling ceph and getting
>> off the mainline track.
> 
> If you're mainly interested in getting rid of the accidentally 1.5PB
> image, you can just delete the header (and id object if it's format 2)
> and then 'rbd rm' will just remove it from the rbd_directory index, and
> not try to delete all the non-existent data objects.

Yes, that's my main interest. Sorry, I haven't yet delved far
into the details of how the rbd stuff hangs together: can you
give me a hint or point me towards any docs regarding what
"delete the header (and id object" would look like?


Cheers,

Chris.