When to restart a dump backup

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A dump backup sometimes does not finish because of internal or external errors, such as tape write errors, power outages, accidental user interruptions, or internal inconsistency on the storage system. If your backup fails for one of these reasons, you can restart it.

You can choose to interrupt and restart a backup to avoid periods of heavy traffic on the storage system or to avoid competition for other limited resources on the storage system, such as a tape drive. You can interrupt a long backup and restart it later if a more urgent restore (or backup) requires the same tape drive. Restartable backups persist across reboots. You can restart an aborted backup to tape only if the following conditions are true:

  • The aborted backup is in phase IV.

  • All of the associated Snapshot copies that were locked by the dump command are available.

  • The file history must be enabled.

When such a dump operation is aborted and left in a restartable state, the associated Snapshot copies are locked. These Snapshot copies are released after the backup context is deleted. You can view the list of backup contexts by using the vserver services ndmp restartable backup show command.

cluster::> vserver services ndmpd restartable-backup show
Vserver     Context Identifier                   Is Cleanup Pending?
----------- ------------------------------------ -------------------
vserver1 330e6739-0179-11e6-a299-005056bb4bc9 false
vserver1 481025c1-0179-11e6-a299-005056bb4bc9 false
vserver2 5cf10132-0179-11e6-a299-005056bb4bc9 false
3 entries were displayed.

cluster::> vserver services ndmpd restartable-backup show -vserver vserver1 -context-id 330e6739-0179-11e6-a299-005056bb4bc9

                       Vserver: vserver1
            Context Identifier: 330e6739-0179-11e6-a299-005056bb4bc9
                   Volume Name: /vserver1/vol1
           Is Cleanup Pending?: false
            Backup Engine Type: dump
Is Snapshot Copy Auto-created?: true
                     Dump Path: /vol/vol1
   Incremental Backup Level ID: 0
                     Dump Name: /vserver1/vol1
     Context Last Updated Time: 1460624875
               Has Offset Map?: true
                 Offset Verify: true
       Is Context Restartable?: true
              Is Context Busy?: false
                  Restart Pass: 4
              Status of Backup: 2
            Snapshot Copy Name: snapshot_for_backup.1
          State of the Context: 7

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