Re: Question about FSHammer getting full

[Sdävtaker <sdavtaker@xxxxxxxxx>]

Im wondering, if I delete a couple of snapshots and prune everything in the machine A, after mirror copy to the second one, it will be pruned and reblocked just by the mirror copy?

On Thu, Aug 27, 2009 at 14:05, Matthew Dillon <dillon@apollo.backplane.com> wrote:

   Thomas, its definitely possible to do both those things.

   Pruning on a per-file basis can be done by carefully specifying the
   key range in the ioctl call to just cover the desired object id
   (inode number).

   Determining how much space the snapshots use can be accomplished by
   scanning the B-Tree.  Some form of the mirror-read ioctl which flags
   the mirror read code to just send the B-Tree records without any of
   the related bulk data (HAMMER_MREC_TYPE_PASS).

   Then the hammer utility can use the mirror-read ioctl with this new
   flag and collect the usage information into buckets based on the
   delete_tid.  The utility can use the prune command's snapshot gathering
   procedures to figure out where the bucket demarkations are.

   I think it all can be done with only a modest amount of work and it
   would be awesome if you did it!

                                               -Matt

-- 
Sdävtaker prays to Rikku goddess for a good treasure.