IBM DS8000 User Manual page 224

gigabyte (GB)
A gigabyte of storage is 10
gigabyte of memory is 2
Global Copy
An optional capability of the DS8000
remote mirror and copy feature that
maintains a fuzzy copy of a logical
volume on the same DS8000 storage unit
or on another DS8000 storage unit. In
other words, all modifications that any
attached host performs on the primary
logical volume are also performed on the
secondary logical volume at a later point
in time. The original order of update is
not strictly maintained. See also Remote
Mirror and Copy and Metro Mirror.
Global Mirror
An optional capability of the remote
mirror and copy feature that provides a
2-site extended distance remote copy.
Data that is written by the host to the
storage unit at the local site is
automatically maintained at the remote
site. See also Metro Mirror and Remote
Mirror and Copy.
group In DS8000 documentation, a nickname for
two different kinds of groups, depending
on the context. See disk pack or Copy
Services server group.
H
HA See host adapter.
HACMP
See high availability cluster multiprocessing.
hard disk drive (HDD)
1) A storage medium within a storage
server used to maintain information that
the storage server requires.
2) A mass storage medium for computers
that is typically available as a fixed disk
(such as the disks used in system units of
personal computers or in drives that are
external to a personal computer) or a
removable cartridge.
hardware service manager
An option on a System i host that enables
the user to display and work with system
hardware resources and to debug
input-output processors (IOP),
input-output adapters (IOA), and devices.
HCD See Hardware Configuration Data.
196
DS8000 User's Guide
9
bytes. A
30
bytes.
HDA See head disk assembly.
HDD See hard disk drive.
hdisk An AIX term for storage space.
head disk assembly (HDA)
The portion of an HDD associated with
the medium and the read/write head.
heartbeat
A status report sent at regular intervals
from the DS8000 storage unit. The service
provider uses this report to monitor the
health of the call home process. See also
call home, heartbeat call home record, and
remote technical assistance information
network.
heartbeat call home record
Machine operating and service
information sent to a service machine.
These records might include such
information as feature code information
and product logical configuration
information.
hierarchical storage management
1) A function in storage management
software, such as Tivoli
Management or Data Facility Storage
Management Subsystem/MVS
™
(DFSMS/MVS
manages free space based on the policy
that the storage administrator sets.
®
2) In AS/400 storage management, an
automatic method to manage and
distribute data between the different
storage layers, such as disk units and tape
library devices.
high availability cluster multiprocessing
(HACMP)
Software that provides host clustering, so
that a failure of one host is recovered by
moving jobs to other hosts within the
cluster.
high-speed loop (HSL)
A hardware connectivity architecture that
links system processors to system
input/output buses and other system
units.
home address
A nine-byte field at the beginning of a
track that contains information that
identifies the physical track and its
association with a cylinder.
®
Storage
), that automatically