Tag Archives: DAG

EMC NMM231 Exchange 2010 DAG backup fails when node has no mounted exchange databases

Networker Module for Microsoft Applications 2.3.1 (2.3.0.build81) is really doing well backing up Microsoft Exchange 2010 DAG configurations.
But a few weeks ago we ran into some strange issue.

Suddenly the Networker group backup was unsuccessful as you can see in the screenshot below, failing with the messages:
“NMM Backup failed to complete successfully” and “nsrsnap_vss_save createInstanceBackup() failed”

After some investigation, we noticed that the other node was doing fine.
And then we saw that all Exchange 2010 databases were mounted on 1 node, the other node without mounted/active databases was having problem.

I posted this on the EMC community and an EMC support engineer commented that this was normal behaviour: “NMM design is if there is not respective backup type mailbox database found while running DAG backup, then we will fail backup.”
So if you have a cluster and for some reason, can’t think of one, but for some reason all databases are mounted on only 1 of the nodes, then NMM will run into problems when trying to backup the “passive” node.

You will have 2 options:
1. Mount a database on the other node
2. disable the Networker Client Resource for the passive exchange node and change for the active exchange node, the networker parameter “NSR_EXCH2010_BACKUP=active -> NSR_EXCH2010_BACKUP=all”.

To me… the above is a dirty-workaround… I would really encourage EMC² to add an extra check into NMM that will not produce this failure, but warn the user in stead.