beautypg.com

HP Hitachi Dynamic Link Manager Software User Manual

Page 498

background image

C. Glossary

476

D

Dev (Device)

A logical division of an LU that HDLM controls and operates. A Dev is equivalent to

a logical volume in AIX.
In an AIX environment, each LU has only one Dev.
Each Dev has a Dev number.
Depending on the access method, Devs are classified into two types: block devices and

character devices.
(See also: Dev number)

Dev number

A number that is assigned to a device within an LU. The device numbers are assigned

sequentially from 0. A Dev number is called a logical volume number in AIX.
HDLM operates assuming that one LU has one Dev, so the device number is fixed to

0

.

(See also: Dev)

E

emulation type

An LU type that is accessible from a host. Since an HDLM management-target host is

an open-system host such as a PC or a UNIX computer, the HDLM management-target

host can access only the LUs that have open-system emulation types.
For details on emulation types supported by a storage system, see the maintenance

manual for that particular storage system.

F

failback

A function for placing the status of a path recovered from an error into the Online

status, and then switching the access path to the path that was just recovered.

failover

A function for switching to another normal path if there is an error in the current access

path, thereby enabling the system to continue to operate.

H

HBA (Host Bus Adapter)

Device that functions as an interface connecting a host with external devices.
In this manual, the term HBA refers to an interface card installed in a host, in