GDDR Tape is a separately licensed product that monitors the Dell Disk Library for mainframe (DLm) operations for DLm systems with either a PowerProtect, Data Domain, PowerScale, or Isilon, and automates DLm Disaster Recovery (DR) testing, and failover and failback processes. GDDR Tape runs on the z/OS system (‘managed LPAR’) and requires no separate GDDR control system, although it can run in a GDDR Control system that supports GDDR for DASD.

GDDR Tape main activities include:

• Actively monitoring the managed environment and responding to exception conditions
• Testing disaster recovery from a snapshot at a remote site
• Running planned and unplanned failover and failback operations

 GDDR Tape supports two topologies:

• Two-Site Long-Distance -- The two-site DLm Long Distance configuration provides disaster restart and disaster testing capabilities at a remote utilizing the asynchronous copy provided by the various supported backend disk systems.
• Three-Site Long-Distance -- The three-site DLm Long Distance configuration provides disaster restart and disaster testing capabilities at either of two remote sites supported by the asynchronous copy feature of various supported backend disk systems.

GDDR Tape can be used with DLm systems that employ PowerScale, PowerProtect, Data Domain or Isilon as backends within the following GDDR topologies:

• Two site SRDF/S with Consistency Group
• Two site SRDF/S with AutoSwap.
• Two site SRDF/A
• Three site SRDF/Star-A

GDDR support for Tape data is also available using PowerMax as a backend disk subsystem. Because GDDR is able to produce consistency across open systems platforms and z/OS, it was natural to apply this capability to the Dell Technologies Disk Library for Mainframe (DLm), because the DLm is simply treated as another open systems host to GDDR. By including a DLm that uses PowerMax 8000, 2500, 8500, or VMAX storage as its backend disk into a GDDR managed consistency group, GDDR is able to provide consistency across tape data and the tape file related metadata stored on DASD, such as the tape catalog, ICF catalog, and DFSMShsm control datasets. This concept is known as ‘Universal Data Consistency’ which is designed to ensure data integrity across tape and DASD in local and remote (synchronous and asynchronous) replication environments using all the topologies supported by GDDR for DASD.

Figure 11.              Universal Data Consistency