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  1. Lustre
  2. LU-1267

LFSCK II: MDT-OST consistency check/repair

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Details

    • New Feature
    • Resolution: Fixed
    • Critical
    • Lustre 2.6.0
    • Lustre 2.6.0
    • 89
    • 3
    • 4024

    Description

      In Lustre, for striped (non-zero striped) file, the layout information for each OST-object is recorded as extended attributes (XATTR_NAME_LOV) in its MDT-object on MDT. Such EA contains the OST index, OID or FID of the OST-object, and so on. On OST-side, each OST-object records the information (MDT-object FID) that indicates which file the OST object belongs to. Over the lifetime of an active filesystem, the layout information in MDT-object's EA may be inconsistent with the information on OST. There are several inconsistent cases as following:

      1. OST-object1 is marked as part of file1 on MDT, but OST-object1 is unassigned or uninitialized on OST.
      2. OST-object1 is marked as part of file1 on OST, but there is no record for OST-object1 on MDT.
      3. OST-object1 is marked as part of file1 on OST, but MDT records that it belongs to file2.
      4. OST-object1 is marked as part of file1 on OST, but both file1 and file2 on MDT claim that it owns OST-object1.

      These inconsistent cases will misguide client/MDS when access related OST-objects, waste space, lose data, even destroy all the system. In LFSCK phase II, we will implement an online tool to check and repair the file layout inconsistency. Such tool will use the inode iterator implemented in LFSCK phase I to scan the whole system, and can be driven together with other LFSCK components.

      On the other hand, the owner information, UID and GID of OST-objects will also be verified to match that of the MDT-object, the inconsistent ones will be fixed, to ensure correct quota allocation.

      Attachments

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          is blocked by

          New Feature - A new feature of the product, which has yet to be developed. LU-3335 LFSCK II: MDT-OST OST local consistency checking

          • Critical - Crashes, loss of data, severe memory leak.
          • Resolved

          New Feature - A new feature of the product, which has yet to be developed. LU-3336 LFSCK II: MDT-OST OST orphan handling

          • Critical - Crashes, loss of data, severe memory leak.
          • Resolved

          New Feature - A new feature of the product, which has yet to be developed. LU-3995 CLONE - LFSCK II: MDT-OST OST local consistency checking

          • Critical - Crashes, loss of data, severe memory leak.
          • Resolved
          is related to

          Story - Created by Jira Software - do not edit or delete. Issue type for a user story. LUDOC-195 Complete Lustre Manual updates for LFSCK Phase II

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

          Task - A task that needs to be done. LUDOC-155 LFSCK Phase II Doc Changes

          • Blocker - Blocks development and/or testing work, production could not run.
          • Resolved

          Improvement - An improvement or enhancement to an existing feature or task. LU-4553 LFSCK 5: LFSCK behaviour if an OST is permanently unavailable

          • Major - Major loss of function.
          • Open

          Improvement - An improvement or enhancement to an existing feature or task. LU-14 live replacement of OST

          • Critical - Crashes, loss of data, severe memory leak.
          • Resolved

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              yong.fan nasf (Inactive)
              yong.fan nasf (Inactive)
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                Created:
                Updated:
                Resolved: