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  1. Lustre
  2. LU-9206

DNE - allow partial access to striped dir if one of the MDTs is unavailable

Details

    • Improvement
    • Resolution: Fixed
    • Minor
    • Lustre 2.15.0
    • None
    • 9223372036854775807

    Description

      Hello,

      Current for stripe dir, if 1 MDT is damaged, the whole dir cannot be accessed. We would like to change/improve the implementation to allow access to partial of the stripe dir on undamaged MDTs.

      use case:
      DIR1 cross 4 MDTs, one of the MDT (Not MDT0) is damaged
      1. Create DIR1 as a striped dir cross all 4 MDTs
      2. Umount MDT1
      3. Data on other undamaged MDT should be accessible

      Attachments

        Issue Links

          is duplicated by

          Bug - A problem which impairs or prevents the functions of the product. LU-9284 striped directory should be able to be accessed even if one stripe MDT is failed.

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

          Bug - A problem which impairs or prevents the functions of the product. LU-17818 LMR: Lustre Metadata Redundancy

          • Major - Major loss of function.
          • Open

          New Feature - A new feature of the product, which has yet to be developed. LU-12310 MDT Device-level Replication/Mirroring

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

          Activity

            [LU-9206] DNE - allow partial access to striped dir if one of the MDTs is unavailable
            pjones Peter Jones made changes -
            Resolution New: Fixed [ 1 ]
            Status Original: Open [ 1 ] New: Resolved [ 5 ]
            pjones Peter Jones added a comment -

            Landed for 2.15

            pjones Peter Jones added a comment - Landed for 2.15
            gerrit Gerrit Updater added a comment -

            "Oleg Drokin <green@whamcloud.com>" merged in patch https://review.whamcloud.com/45631/
            Subject: LU-9206 llite: access striped directory with missing stripe
            Project: fs/lustre-release
            Branch: master
            Current Patch Set:
            Commit: c0fa6f7a10d1162f8d49d40ab4f5aba80e72157e

            gerrit Gerrit Updater added a comment - "Oleg Drokin <green@whamcloud.com>" merged in patch https://review.whamcloud.com/45631/ Subject: LU-9206 llite: access striped directory with missing stripe Project: fs/lustre-release Branch: master Current Patch Set: Commit: c0fa6f7a10d1162f8d49d40ab4f5aba80e72157e
            adilger Andreas Dilger made changes -
            Summary Original: DNE - allow partially access to striped dir if 1 of the multiple MDTs is damaged New: DNE - allow partial access to striped dir if one of the MDTs is unavailable
            adilger Andreas Dilger made changes -
            Labels Original: dne3 New: LMR dne3
            adilger Andreas Dilger made changes -
            Link New: This issue is related to EX-4404 [ EX-4404 ]
            adilger Andreas Dilger made changes -
            Link New: This issue is related to LU-12310 [ LU-12310 ]
            gerrit Gerrit Updater added a comment -

            "Lai Siyao <lai.siyao@whamcloud.com>" uploaded a new patch: https://review.whamcloud.com/45631
            Subject: LU-9206 llite: access striped directory with missing stripe
            Project: fs/lustre-release
            Branch: master
            Current Patch Set: 1
            Commit: 8982e179d90eed2baa8845468d317c2f10c43ad2

            gerrit Gerrit Updater added a comment - "Lai Siyao <lai.siyao@whamcloud.com>" uploaded a new patch: https://review.whamcloud.com/45631 Subject: LU-9206 llite: access striped directory with missing stripe Project: fs/lustre-release Branch: master Current Patch Set: 1 Commit: 8982e179d90eed2baa8845468d317c2f10c43ad2
            pjones Peter Jones made changes -
            Fix Version/s New: Lustre 2.15.0 [ 14791 ]
            Fix Version/s Original: Lustre 2.14.0 [ 14490 ]
            adilger Andreas Dilger added a comment -

            Lai,
            I think this problem of accessing a directory with offline stripes is already fixed? Is there already a test for this? If yes, then this should be linked to the patch that fixed the problem.

            If not, then test could do something like:

            • create striped directory
            • create 100 files in it
            • "lfs getstripe -m" all entries to determine which MDT each file is on
            • take one MDT offline
            • "ls -l" directory to check that entries for online MDTs are still available
            • verify that none of the offline entries are listed
            • verify that "ls -l' returns an error at the end
            • take MDT online
            • verify that all files are accessible again.
            adilger Andreas Dilger added a comment - Lai, I think this problem of accessing a directory with offline stripes is already fixed? Is there already a test for this? If yes, then this should be linked to the patch that fixed the problem. If not, then test could do something like: create striped directory create 100 files in it " lfs getstripe -m " all entries to determine which MDT each file is on take one MDT offline " ls -l " directory to check that entries for online MDTs are still available verify that none of the offline entries are listed verify that " ls -l ' returns an error at the end take MDT online verify that all files are accessible again.

            People

              laisiyao Lai Siyao
              sarah Sarah Liu
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              Dates

                Created:
                Updated:
                Resolved: