NetWorker: Backup to Data Domain fails with Stale File Handle Errors

• Backups going to Data Domain fails with the following errors:

202836:save: Unable to write to a file due to stale handle.
The error message is: [5057] [10456] [4084] Tue Apr 21 23:56:36 2026
ddp_write() failed Offset 20732444672, BytesToWrite 524288, BytesWritten 0 Err: 5057-File handle is stale
86699:save: Unable to write data into multiple buffers for save-set ID 'xxxxxx': File handle reference is no longer available.
(errno=149)
74209:save: Quit signal received.
99123:save: Handling an abort while processing Windows backup.
90097:save: ASR Backup: aborting VSS volume save because Quit flag is set.
146001:save: Unable to sync file system for save-set ID 'xxxxxx': DD boost operation aborted on entry because Quit flag is set
209610:save: DD boost operation aborted on entry because Quit flag is set

• Some save sets may complete successfully while others fail with the above errors.

The issue occurs when NetWorker attempts to write to a file handle that has already been closed.
In these scenarios, the file handle is marked as abandoned by Data Domain after 3 hours of inactivity (default timeout).
For busy clients or large backups, additional time may be required to consolidate data, causing the backup to exceed the default abandonment timeout and resulting in a stale file handle.

To address this issue, increase the OST_ABANDON_TIMEOUT value to allow additional time for backup consolidation.

By increasing the timeout value, you can prevent the file handle from being closed prematurely, thus avoiding the stale file handle error during file system synchronization.

Recommended timeout: 8 hours (28,800 seconds)
In rare scenarios, it may be increased up to 12 hours (43,200 seconds)