Question about FSHammer getting full

Sdävtaker sdavtaker at gmail.com
Thu Aug 27 11:14:51 PDT 2009


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 at 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.




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