Data Domain: Unity Sync Replication Port cannot be used to connect VTL drives
Summary: Unity Sync Replication Port cannot be used for 2-way Network Data Management Protocol (NDMP).
Symptoms
New Virtual Tape Library (VTL) drives configured on Data Domain for Unity NAS cannot be discovered.
Cause
If the Sync Replication Port on Unity NAS is configured on Data Domain as an initiator for VTL devices, Unity is unable to discover those devices.
Resolution
If Unity NAS is unable to discover Data Domain VTL drives, check that the configuration is supported and follow VTL and Access Group Best Practices:
- As of March 2020, OE 4.4 is the only supported Unity software release with Data Domain VTL. Check the Compatibility Guide for updates: Data Domain Hardware NAS Compatibility Guide
- LUN numbering in the Access Group should always start at LUN zero and maintain contiguous LUN numbering sequences from zero for every target port.
- According to Deployment KB: Unity- How to configure 2-Way NDMP backup in Unity Fibre Channel (FC) direct connect is not supported.
After completing all the above steps, if the issue is not fixed check if the Unity port used as initiator is a Sync Replication Port.
Refer to Dell EMC Unity: How to find the Sync Replication Ports (User Correctable) to identify ports configured as Sync Replication Ports directly on Unity NAS or check Unity logs (Service Data or Data collects).
If the Unity FC Port zoned to DD VTL is configured as Sync Replication Port, you must select a different FC port on Unity for 2-way NDMP and change your zoning accordingly.