More Information - HP D2D Manual

Figure 4 Data center to data center recovery with physical tape offload
In this scenario, there are two locations:
Site A is the production site where data is backed up to a local D2D Backup System.
Site B is used for DR purposes to maintain a secondary copy of the data and to archive copies
to tape.
Two D2D Backup Systems are provided, one in each location, together with dedicated Media
Agent servers for each library. At Site A, the Commserve acts as the Media Agent for the local
D2D device (D2D-A); whist the second Media Agent server is connected to D2D –B at the DR
location (Site B).
D2D-A is configured to replicate data stored to it to D2D-B via Low Bandwidth Replication (LBR).
In addition, the Media Agent server at Site B is also connected to a Tape Library. Both D2D Backup
Systems and Media Agents are configured as a CommVault replica disk library, with the primary
path (read/write) through Media Agent connected to D2D-A; and the read-only path via Media
Agent connected to D2D-B. An additional Tape Library is configured for the Media Agent at Site
B.
Using this configuration it is possible for archive copies to tape to be performed solely from Site
B, i.e. without impacting on Site A or the WAN connection between the sites, whilst being under
the control of the CommServe at Site A.
This is achieved by scheduling an Auxiliary Copy of the backup data (CommVault terminology for
a second copy) that would use Media Agent at Site B to read the data from D2D-B (replica D2D),
and to copy the data by writing it out to the tape library also configured on the same Media Agent.

More Information

See:- CommVault Disk Libraries
Data center to data center with physical tape offload at DR site 45