StorageTek SL8500, User Manual

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World Wide Name
Glossary-9
virtual tape drive (VTD)
An emulation of a physical transport in the VTSS that looks like a physical tape
transport to MVS. The data written to a VTD is really being written to DASD. The
VTSS has 64 VTDs that do virtual mounts of VTVs.
virtual tape storage subsystem (VTSS)
The DASD buffer containing virtual volumes (VTVs) and virtual drives (VTDs). The
VTSS is a STK RAID 6 hardware device with microcode that enables transport
emulation. The RAID device can read and write "tape" data from/to disk, and can read
and write the data from/to an RTD.
virtual tape volume (VTV)
A portion of the DASD buffer that appears to the operating system as a real tape
volume. Data is written to and read from the VTV, and the VTV can be migrated to
and recalled from real tape.
WWN
See World Wide Name .
World Wide Name
A 64-bit address that uniquely identifies each individual device and vendor, much like
the MAC address of an Ethernet interface. Each port on a Fibre Channel network must
have a its own WWN. The WWN is not just a physical hardware address. It also serves
as the logical address of a node on the SAN. The SAN configuration changes if any of
the attached hardware changes. If a device fails and is replaced, the WWN of the node
changes, forcing reconfiguration of the SAN. There are three World wide Names
reserved for each drive bay: Node, Port A, and Port B.