Avamar: NDMP Backup Fails When Exclude Lists Differ Between Full and Incremental

 Backup Failure Indicators for Avamar NDMP with Exclude Settings.

The following symptoms are observed when an NDMP backup job includes an Exclude list that differs between the base (full) backup and subsequent incremental backups.

• Backup job terminates with a failure status during the incremental run.
• Log entries report a mismatch between the exclude directories defined for the base backup and those for the incremental backup.
• A warning is generated indicating that the exclude list for the incremental backup differs from the base backup.

2019-02-04 19:02:18 avndmp Info <41855>: [snapup-/vol/xxxx_cifs] EXCLUDE directories for target path: /vol/xxx_cifs/ are: *.ost
2019-02-04 19:02:18 avndmp Info <0000>: [snapup-/vol/xxx_cifs] EXCLUDE directories: *.ost for incremental backup of /vol/xxx_cifs/ is different from EXCLUDE directories: for base backup
2019-02-04 19:02:18 avndmp Warning <18451>: [snapup-/vol/xxx_cifs] EXCLUDE for incremental backup is different from the base backup, target path: /vol/xxx_cifs/

Impact of Mismatched Exclude Lists on NDMP Backups.

When the exclude list defined for a full backup differs from the exclude list defined for an incremental backup, the Avamar NDMP client encounters inconsistent backup criteria.
This inconsistency triggers different outcomes based on the incremental backup policy set in the dataset.

Behavior Based on Incremental Backup Policy

• Prefer incremental (fallback to full if required): The client automatically performs a full backup when the exclude lists do not match.
• Force incremental (level 1): The client attempts an incremental backup despite the mismatch, resulting in a backup failure.

Relevant Log Messages

2019-02-04 19:02:18 avndmp Info <41855>: [snapup-/vol/xxxx_cifs] EXCLUDE directories for target path: /vol/xxx_cifs/ are: *.ost
2019-02-04 19:02:18 avndmp Info <0000>: [snapup-/vol/xxx_cifs] EXCLUDE directories: *.ost for incremental backup of /vol/xxx_cifs/ is different from EXCLUDE directories: for base backup
2019-02-04 19:02:18 avndmp Warning <18451>: [snapup-/vol/xxx_cifs] EXCLUDE for incremental backup is different from the base backup, target path: /vol/xxx_cifs/

Restore Normal NDMP Backup Operation.

Step‑by‑Step Resolution

Follow these steps to clear the EXCLUDE mismatch and allow incremental NDMP backups to complete.

• Identify the volume that reports the EXCLUDE warning such as

  /vol/xxx_cifs

• Verify that the exclude list for the base (full) backup matches the list defined for incremental backups. If they differ, edit the dataset so both lists are identical.
• Run a full (level 0) backup for the affected volume.
• After the full backup finishes successfully, run an incremental (level 1) backup.

These actions reset the backup state and align the exclude definitions, eliminating the warning and preventing backup failure.
 

Starting the Backups

Use the Avamar Administrator console or the command‑line interface (CLI) to start the backups.

# Example CLI command to start a full (level 0) backup
avtar -b -l 0 -v /vol/xxx_cifs

# Example CLI command to start an incremental (level 1) backup
avtar -b -l 1 -v /vol/xxx_cifs

Replace the below path with the path of the problematic volume.

/vol/xxx_cifs 

Verification

• Open the Avamar backup logs 

  /var/log/avamar/avndmp.log

  • And confirm that no "EXCLUDE for incremental backup is different from the base backup" warnings appear.
• Ensure that the backup status shows Completed for both the full and subsequent incremental runs.
• Run an NDMP restore test to verify data integrity, if required.