Network Router User Manual

Volume

An IBM

ESA/390

term for the information recorded on a single disk unit or

recording medium. Indirectly, a volume can refer to the unit of recording medium

itself. On a non-removable medium storage device such as a disk drive, the terms may

also refer, indirectly, to the storage device that is associated with the volume. When a

user stores multiple volumes on a single storage medium transparent to the program,

the volumes are referred to as logical volumes.

WAN

Wide Area Networks or WANs are networks of computers that are geographically

dispersed and connected by radio waves, telephone lines, satellites, or high-speed fiber

optic backbones.

Workload

I/O workload refers to the pattern of I/Os presented to the Hitachi Freedom Storage

™

Lightning 9900

™

V Series system or to a disk drive.

WWN

World Wide Name(s) or WWN(s) refer to an eight-byte identifier assigned to each

product that can be used as a port on a Fibre Channel network. The WWN is stored

in nonvolatile memory and is frequently stamped on the surface of the product or used

as a serial number. It applies to all HBAs, switches, or storage controller cards that

interface to a Fibre Channel network.

XRC

Extended Remote Copy. The IBM implementation of a software asynchronous remote

copy technique that preserves data integrity. See also HXRC and Hitachi TrueCopy

™

zOS

™

IBM’s latest mainframe operating system.

Hitachi Data Sy s t e m s