Describes how you can use the gfsck command, under the supervision of MapR Support or Engineering, to perform consistency checks and appropriate repairs on a volume, or a volume snapshot.

You can use the gfsck command when the local fsck either repairs or loses some containers at the highest epoch.


    [ -h|--help ]
    [ -c|--clear ]
    [ -d|--debug ]
    [ -b|--dbcheck ]
    [ -r|--repair ]
    [ -y|--assume-yes ]
    [ cluster=<cluster name> ]
    [ rwvolume=<volume name> ]
    [ snapshot=<snapshot name> ]
    [ snapshotid=<snapshot-id> ]




User who must use this option
-h|--help Prints usage text. root, as well as mapr
-c|--clear Clears previous warnings before performing the global filesystem check. root
-d|--debug Provides information for debugging. root
-b|--dbcheck Checks that every key in a tablet is within that tablet's startKey and endKey range. As this option is I/O intensive, use this option only if you suspect database inconsistency. root
-y --assume-yes If specified, assumes that containers without valid copies (as reported by CLDB) will be deleted automatically. If not specified, gfsck pauses for user input: yes to delete, no to exit gfsck, or ctrl-C to quit. root
cluster Specifies the name of the cluster (default: default cluster) root
rwvolume Specifies the name of the volume (default: null) root
snapshot Specifies the name of the snapshot (default: null) root
snapshotid Specifies the snapshot ID (default: 0) root

Example (Debug mode)

In debug mode, run the gfsck command on the read/write volume named mapr.cluster.root:

/opt/mapr/bin/gfsck rwvolume=mapr.cluster.root -d

Sample output is as follows:

Starting GlobalFsck:
  clear-mode            = false
  debug-mode            = true
  dbcheck-mode          = false
  repair-mode           = false
  assume-yes-mode       = false
  cluster               =
  rw-volume-name        = mapr.cluster.root
  snapshot-name         = null
  snapshot-id           = 0
  user-id               = 0
  group-id              = 0

  get volume properties ...
    rwVolumeName = mapr.cluster.root (volumeId = 205374230, rootContainerId = 2049, isMirror = false)

  put volume mapr.cluster.root in global-fsck mode ...

  get snapshot list for volume mapr.cluster.root ...

  starting phase one (get containers) for volume mapr.cluster.root(205374230) ...
    container 2049 (latestEpoch=3, fixedByFsck=false)
    got volume containers map
  done phase one

  starting phase two (get inodes) for volume mapr.cluster.root(205374230) ...
    get container inode list for cid 2049
      +inodelist: fid=2049.32.131224 pfid=-1.16.2 typ=4 styp=0 nch=0 dMe:false dRec: false
      +inodelist: fid=2049.33.131226 pfid=-1.16.2 typ=2 styp=0 nch=0 dMe:false dRec: false
      +inodelist: fid=2049.34.131228 pfid=-1.33.131226 typ=4 styp=0 nch=0 dMe:false dRec: false
      +inodelist: fid=2049.35.131230 pfid=-1.16.2 typ=4 styp=0 nch=0 dMe:false dRec: false
      +inodelist: fid=2049.36.131232 pfid=-1.16.2 typ=4 styp=0 nch=0 dMe:false dRec: false
      +inodelist: fid=2049.38.262312 pfid=-1.16.2 typ=2 styp=0 nch=0 dMe:false dRec: false
      +inodelist: fid=2049.39.262314 pfid=-1.38.262312 typ=1 styp=0 nch=0 dMe:false dRec: false
    got container inode lists (totalThreads=1)
  done phase two

  starting phase three (get fidmaps & tabletmaps) for volume mapr.cluster.root(205374230) ...
    got fidmap lists (totalFidmapThreads=0)
    got tabletmap lists (totalTabletmapThreads=0)
  done phase three

  === Start of GlobalFsck Report ===

  file-fidmap-filelet union --
   2049.39.262314:P     --> primary (nchunks=0)      --> AllOk
    no errors

  table-tabletmap-tablet union --

  orphan directories --

  orphan kvstores --

  orphan files --

  orphan fidmaps --

  orphan tables --

  orphan tabletmaps --

  orphan dbkvstores --

  orphan dbfiles --

  orphan dbinodes --

  containers that need repair --

  incomplete snapshots that need to be deleted --

  user statistics --
    containers          = 1
    directories         = 2
    kvstores            = 0
    files               = 1
    fidmaps             = 0
    filelets            = 0
    tables              = 0
    tabletmaps          = 0
    schemas             = 0
    tablets             = 0
    segmaps             = 0
    spillmaps           = 0
    overflowfiles       = 0
    bucketfiles         = 0
    spillfiles          = 0

  === End of GlobalFsck Report ===

  remove volume mapr.cluster.root from global-fsck mode (ret = 0) ...

GlobalFsck completed successfully (7142 ms); Result: verify succeeded