HP Cisco Nexus 5000 Cisco MDS 9000 Family CLI Configuration Guide - Release 4. - Page 738

FICON Tape Acceleration Chapter 29 Configuring FICON Send documentation comments to [email protected] Step 3 Issue the no shutdown command on each port to enable traffic flow. Note If you specify the ficon swap interface old-interface new-interface after swap noshut command, the ports are automatically initialized. FICON Tape Acceleration The sequential nature of tape devices causes each I/O operation to the tape device over an FCIP link to incur the latency of the FCIP link. Throughput drastically decreases as the round-trip time through the FCIP link increases, leading to longer backup windows. Also, after each I/O operation, the tape device is idle until the next I/O arrives. Starting and stopping of the tape head reduces the lifespan of the tape, except when I/O operations are directed to a virtual tape. Cisco MDS NX-OS software provides acceleration for the following FICON tape write operations: • The link between mainframe and native tape drives (both IBM and Sun/STK) • The back-end link between the VSM (Virtual Storage Management) and tape drive (Sun/STK) FICON tape acceleration over FCIP provides the following advantages: • Efficiently utilizes the tape device by decreasing idle time • More sustained throughput as latency increases • Similar to FCP tape acceleration, and does not conflict with it Note FICON tape read acceleration over FCIP is not supported. Figure 29-5 through Figure 29-8 show supported configurations: Figure 29-5 Host Directly Accessing IBM/STK (StorageTek) Library 144880 FICON IBM OS/390 Cisco MDS FICON over FCIP FICON Cisco MDS Tape library Figure 29-6 Host Accessing Standalone IBM-VTS (Virtual Tape Server) /STK-VSM (Virtual Shared Memory) FICON over FCIP VSM FICON over FCIP Cisco MDS Tape library 144881 29-38 Cisco MDS 9000 Family CLI Configuration Guide OL-18084-01, Cisco MDS NX-OS Release 4.x