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  1. Lustre
  2. LU-12926

lfs mkdir -c can cause repeated MDT indexes

Details

    • Bug
    • Resolution: Cannot Reproduce
    • Major
    • None
    • Lustre 2.13.0, Lustre 2.12.3
    • 3
    • 9223372036854775807

    Description

      For a large (e.g. 5) number of MDTs, doing the following:

      lfs mkdir -c 5 dir/

      Can yield an MDT distribution of: 4, 0, 4, 1, 2 or other distributions with repeated and missing mdt indexes.

      Manually specifying mdts via -i works as expected.

      I believe this is due to the "auto_distributed" logic in lustre/utils/lfs.c::lfs_setdirstripe()

      Attachments

        Issue Links

          is related to

          Improvement - An improvement or enhancement to an existing feature or task. LU-17756 tunable limit for MDT overstripe factor

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Resolved
          is related to

          New Feature - A new feature of the product, which has yet to be developed. LU-12273 DNE3: Metadata overstriping

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Resolved

          Activity

            [LU-12926] lfs mkdir -c can cause repeated MDT indexes
            adilger Andreas Dilger added a comment -

            I haven't seen any reports of this lately, and no reproducer available. Please re-open if this is hit again.

            adilger Andreas Dilger added a comment - I haven't seen any reports of this lately, and no reproducer available. Please re-open if this is hit again.
            adilger Andreas Dilger added a comment -

            We should add basic sanity checking on the MDS to avoid this. It should limit the stripe count to the number of available MDTs rather than return an error.

            adilger Andreas Dilger added a comment - We should add basic sanity checking on the MDS to avoid this. It should limit the stripe count to the number of available MDTs rather than return an error.
            adilger Andreas Dilger added a comment -

            It shouldn't be possible to do this with "-c", only when the metadata overstripingpatch adds the "-C" option.

            adilger Andreas Dilger added a comment - It shouldn't be possible to do this with "-c", only when the metadata overstripingpatch adds the "-C" option.

            People

              laisiyao Lai Siyao
              utopiabound Nathaniel Clark
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              Dates

                Created:
                Updated:
                Resolved: