IBM Tape Solutions for Storage Area Networks and FICON

104 IBM Tape Solutions for Storage Area Networks and FICON

For more information about the 3494 subsystems, see either of these sites:

http://www.storage.ibm.com/hardsoft/tape/3494/index.html

http://www.storage.ibm.com/hardsoft/tape/3494_vts/index.html

The IBM 3494-B18 Virtual Tape Server has the option of two or four SCSI interfaces. For a

VTS Model B10 or B20 the maximum number of SCSI interfaces is eight. These can be

attached to a SAN by using the IBM 2108-G07 SAN Data Gateway. For more details about

the interface intermix capabilities, see 6.5, “IBM 3494 Virtual Tape Server” on page 167. A

separate LAN or RS-232 connection is required from attached servers to the 3494 library

manager. Note that a Peer-to-Peer VTS cannot have SCSI interfaces and, therefore, cannot

be attached to a SAN.

Figure 4-9 IBM TotalStorage 3494 Enterprise Tape Library

4.5 Digital Linear Tape and SuperDLT

Digital Linear Tape (DLT) technology is owned, developed, and manufactured by Quantum

Corporation who bought the technology from Digital Equipment. DLT technology uses linear

recording and writes each data track on the entire length of the tape (about 1,800 feet for

DLTtape IV media). Data is first written onto a track along the entire length of the tape, and

when the end is reached the heads are repositioned to record a new track again, along the

entire length of the tape, now travelling in the opposite direction. This continues back and

forth until the tape is full. Current DLT drives record either 128 tracks (DLT 2000XT and DLT

4000 drives) or 208 tracks (DLT 7000 and DLT 8000) on half-inch tape.

Quantum is also developing Super DLTtape technology. Super DLTtape uses Advanced Metal

Particle (AMP) technology and Laser Guided Magnetic Recording to increase the native

capacity of Super DLTtape media to more than 100 GB.