NetWorker: Azure VM Snapshot Backups Failing as Current Session has Exceeded Server Parallelism

Summary: NetWorker Azure Virtual Machine (VM) Snapshot backups fail. The error reported is "current save session has exceeded NetWorker server's parallelism"

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

The following error is observed in the NetWorker Azure VM backup's policy logs:

  • Linux: /nsr/logs/policy/POLICY_NAME/WORKFLOW_NAME
  • Windows (Default): C:\Program Files\EMC NetWorker\nsr\logs\policy\POLICY_NAME\WORKFLOW_NAME
nsrazure_save: RESOURCE_GROUP_NAME:VM_NAME:DISK_NAME level=full, 0 KB 00:00:01      0 files
207818:nsrazure_save:Cannot intialize backup. Backup of Saveset: RESOURCE_GROUP_NAME:VM_NAME:DISK_NAME failed with error current save session has exceeded NetWorker server's parallelism.
207824:nsrazure_save:Backup of Saveset: RESOURCE_GROUP_NAME:VM_NAME:DISK_NAME failed.
174908:nsrazure_save:Saving the backup data in the pool 'POOL_NAME'.
206529:nsrazure_save: Unable to set up the direct save with server 'NW_SERVER_NAME'. Be sure network connectivity exists between client 'CLIENT_NAME' and storage node '?' in both directions. Error: current save session has exceeded NetWorker server's parallelism
90018:nsrazure_save: Cannot open a nsrazure_save session with NetWorker server 'NW_SERVER_NAME': current save session has exceeded NetWorker server's parallelism

Cause

The NetWorker server's parallelism is too low. 

The server parallelism attribute controls how many save streams the server accepts simultaneously. The more save streams that the server can accept, the faster the devices and client disks run. Client disks can run at their performance limit or the limits of the connections between them. Server parallelism is not used to control the startup of backup jobs, but as a final limit of sessions accepted by a backup server. The server parallelism value should be as high as possible while not overloading the backup server itself.

Resolution

Increase the NetWorker server's parallelism setting. Server Parallelism is detailed in the NetWorker Performance Optimization and Planning Guide, on Dell Support.

  1. Open an Administrator command-prompt or root shell on the NetWorker server.
  2. Run the command nsradmin.
  3. On the nsradmin prompt, enter show parallelism.
  4. On the nsradmin prompt, enter print type: nsr
The NetWorker server's parallelism setting is displayed.
  1. To increase the parallelism, enter update parallelism: new_value

The default server parallelism is 32, but can be increased up to 1024. The values use binary progressions such as 32, 64, 128, 256, 512, 1024.


NOTE: If you schedule more than 50 concurrent clone workflows in a data zone, ensure that you configure the server parallelism value to 1024. This is to avoid the starvation of streams reserved by clone operation.
 
  1. You are prompted to confirm the changes, enter y or yes.
  2. Enter q or quit to exit nsradmin.

Example:

[root@nsr ~]# nsradmin
NetWorker administration program.
Use the "help" command for help, "visual" for full-screen mode.
nsradmin> show parallelism
nsradmin> print type: nsr
                 parallelism: 32;
nsradmin> update parallelism: 1024
                 parallelism: 1024;
Update? y
updated resource id 3.0.10.33.0.0.0.0.251.130.220.103.192.168.9.150(75)
nsradmin> print
                 parallelism: 1024;
nsradmin> q

Affected Products

NetWorker

Products

NetWorker Family
Article Properties
Article Number: 000358771
Article Type: Solution
Last Modified: 02 Oct 2025
Version:  2
Find answers to your questions from other Dell users
Support Services
Check if your device is covered by Support Services.