HP ProLiant Cluster HA/F500 for Enterprise Virtual Array Enhanced DT Supplement Guide

Glossary
host
The primary or controlling computer to which a storage system is attached.
host bus adapter (HBA)
A device that connects a host system to a SCSI bus. The host bus adapter usually performs
the lowest layers of the SCSI protocol. This function may be logically and physically
integrated into the host system.
initiator site
The location of the primary network.
latency
The amount of time required for a transmission to reach its destination.
local site
The location of the primary network.
logical unit (LUN)
A physical or virtual device addressable through a target ID number. LUNs use the target bus
connection to communicate on the SCSI bus. The host sees a virtual disk as a LUN.
logical unit number
1. A value that identifies a specific logical unit belonging to a SCSI target ID number.
2. A number associated with a physical device unit during the I/O operations of a task. Each
task in the system must establish its own correspondence between logical unit numbers and
physical devices.
mirror
A duplicate data image maintained on a separate storage array. In an HA/F500 Enhanced DT
configuration, data is mirrored at a remote site. If a drive in the primary (initiator) storage
subsystem fails, its mirror drive in the remote (target) storage subsystem can provide an exact
copy of the data.
HP ProLiant Cluster HA/F500 for Enterprise Virtual Array Enhanced DT Supplement Guide Glossary-3
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Writer: Bill Akers File Name: w-glossary
Codename: Chargers II Part Number: 339223-001 Last Saved On: 5/29/03 2:44 PM