Source Pool: Unreferenced container (debris)

  • Description: Source pool includes a data container that is not referenced by the VOB database. Such containers are tentatively classified as debris, but must pass several tests before being moved to the applicable pool’s lost+found directory.
  • Causes: Any of the following, depending on whether the database or the pool has the more recent reference time:
    • (Database newer) Database references the new container name (which is missing), but pool stores older, unreferenced container.
    • (Database newer) Database records rmver or rmbranch events, but older pool stores container with branches or versions still in place.
    • (Pool newer) Pool has container with versions from one or more checkin operations not recorded in the older database.
    • (Pool or database reference times differ) A chpool operation on a file element in the interval between pool and database reference times leaves the database pointing at the wrong pool and the containers unreferenced.
    • Restoring a pool from incremental backups.
    • Unexpected events.
  • Fix processing: The checkvob command usually moves an unreferenced container to the pool’s lost+found subdirectory. It does not move unreferenced containers that fit these categories:
    • May be needed. checkvob found, but did not fix, a missing container problem, and the pathname of the current unreferenced container suggests that it may be able to contribute to reconstruction of the missing container on a subsequent checkvob run. If you specify –fix and –debris without specifying –data, checkvob performs –data check processing to identify debris that may be needed, but does not perform –fix processing.
    • Underage. The container is less than one hour old. The checkvob command skips underage containers to avoid removing a newly created container before the VOB database has been updated to reference it. Typically, the time between new container creation and database reference update is less than one second, but checkvob takes a conservative approach because of the critical nature of source containers.
    • Scheduled for deletion. The VOB is configured for deferred source container deletion (see the vob_snapshot_setup reference page), and the container is already marked for deletion.
Note: When the pool is newer than the database and includes more recent versions not recorded in the (older) database, checkvob does not salvage versions from the unreferenced containers and update the database. It uses the unreferenced containers to return the pool to the state expected by the database, and it moves the unreferenced containers (with the latest version data) to the pool’s lost+found directory. These versions should be presumed lost. For more information, contact HCL Customer Support.