Recently we ran into an issue where Avamar 7 backups failed when attempting to backup and Exchange 2013 DAG (with Windows Server 2012 nodes). The issue was seen every time a mailbox database backup was attempted from the Avamar DAG client, and the mailbox database copy also resided on the same node (local name resolution via NetBIOS name).
During the investigation into the issue, we discovered that the IP Address that was being returned was non-routable address (the internal cluster communication IP of the failover cluster).
The following logs were seen in Avamar Administrator:
2014-07-03 23:06:41 avexvss Info <13057>: Waiting for a VSS snapshot synchronization event from the initiating plugin.
2014-07-03 23:11:04 avexvss Info <16153>: Cancel request received
2014-07-03 23:11:41 avexvss Error <13058>: Timed out while waiting for the update status message.
To resolve this issue the following lines were entered into the AVEXVSS.CMD file (on the /var share defined during the DAG client configuration):
This ensured that all communication to the DAG nodes from the DAG client was performed over the defined IP Address.