Avamar: NDMP Snapshots Are Retained On Isilon OneFS After Backup Job Finishes

Summary: Avamar NDMP (Network Data Management Protocol) backup finishes successfully, but Isilon OneFS retains multiple snapshots.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.
Check out other resources

Symptoms

Avamar NDMP (Network Data Management Protocol) backup finishes successfully, but Isilon OneFS retains multiple snapshots: 
isilon# isi snapshot list | grep ndmp
316  ndmp_backup_1781d7102ea9a04cca1c64bf63e469bc_1640598135_1 /ifs
320  ndmp_backup_1781d7102ea9a04cca1c64bf63e469bc_1640598287_1 /ifs
326  ndmp_backup_2dd99b185b808c4c00bc77897ffd8395_1643189414_1 /ifs/test
330  ndmp_backup_2dd99b185b808c4c00bc77897ffd8395_1643882168_1 /ifs/test
332  ndmp_backup_b124250821636fcfe2339e7f13a2ad23_1643882192_1 /ifs/test
There are two BACKUP_MODEs, which get passed through the backup server:
  • TIMESTAMP (default): Deletes the NDMP snapshot at the end of the job
  • SNAPSHOT: Retains up to three NDMP snapshots per file system. The next time the NDMP job runs, it will roll the oldest snapshot off

Cause

Root Cause of the Issue

The root cause of the issue is related to the handling of NDMP snapshots on Isilon OneFS version 9.x.

Starting with Isilon OneFS 9.x version, NDMP snapshots are not properly handled or not deleted because of the BACKUP_OPTIONS(7) parameter.

Specific Conditions

The issue is related to the BACKUP_MODEs, which get passed through the backup server, including TIMESTAMP (default) and SNAPSHOT.

The SNAPSHOT mode retains up to three NDMP snapshots per file system. The next time the NDMP job runs, it will roll the oldest snapshot off and add the current snapshot.

isi ndmp settings global view
 

The output of the above command would be:

Setting Value
------------------------------------
port 10000
dma generic

Resolution

Fixing the Issue of Avamar NDMP Backup Finishing Successfully but Isilon OneFS Retaining Multiple Snapshots

To resolve the issue, ensure that the DMA(Data Management Application) is set to generic. Run the following command on Isilon to check the current setting:

  
isi ndmp settings global view
Output would be: 
Setting Value
------------------------------------
port 10000
dma generic

Download and apply the relevant hotfix for your Avamar version. The available hotfixes are:

If the hotfix is not available for download, contact Dell Support for assistance.

Caution: Before applying any hotfix, ensure you review the README file for instructions and contact Dell Support if you have any concerns.

19.7 - Hotfix 336034

19.4 - Hotfix 336033

Contact Dell Support if hotfix is not available to download.

Affected Products

Avamar, Avamar Plug-in for NDMP, Isilon
Article Properties
Article Number: 000216876
Article Type: Solution
Last Modified: 08 Jan 2026
Version:  7
Find answers to your questions from other Dell users
Support Services
Check if your device is covered by Support Services.