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HP XP P9500 Storage User Manual

Page 484

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When an error occurs on a path that was in the Online status, path health checking

changes the status of the path to the Offline(E) status.

Path health checking checks only those paths that have the Online status.

path name

The path name consisting of the following four elements, separated by periods:

- HBA adapter number or adapter type (character string)

- Bus number or adapter number (character string)

- Target ID (hexadecimal number)

- Host LU number (hexadecimal number)

A path name is used to identify a path.

(See also: host LU number)

persistent reservation

Similar to reservations, persistent reservations enable a server to declare that it has

exclusive rights to use an LU, and prevents other servers from accessing that LU. Note,

however, that while reservations allows a server to have exclusive use of only one path

to the LU, persistent reservations allow a server to have exclusive rights to use multiple

paths.

If persistent reservations are used in HDLM, a host can have exclusive use of multiple

paths to an LU, so that load balancing among these paths is possible.

(See also: reservation)

R

reservation

The reservation function enables a host to declare that it has exclusive rights to use a

particular LU, and prevents other hosts from accessing that LU. Access permission for

an LU that has been reserved is given only to the host that issued the reservation, so

the LU cannot be accessed from multiple paths (coming from multiple hosts)

simultaneously. However, because of this, load balancing is not possible.

(See also: persistent reservation)

S

SAN (Storage Area Network)

A high-speed network connecting hosts to and storage systems. This network is

independent of a LAN and is dedicated to data transfers. A SAN provides faster access

to storage systems, and prevents the transfer of high-volumes of data from

deteriorating LAN performance.

SCSI device

A SCSI disk device

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Glossary-6

Hitachi Dynamic Link Manager User Guide for AIX

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