IBM System storage DS6000 Series, Attachment Manual, Page: 268 / 298

on the same DS6000 or on another
DS6000. 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 DS6000
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 DS6000 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
Multi-Processing .
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 (HSM)
An option on an AS/400 or iSeries 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 .
HDA See head and disk assembly .
HDD See hard disk drive .
hdisk An AIX term for storage space.
head and 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 DS6000. 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 Storage
Management or Data Facility Storage
Management Subsystem/MVS
(DFSMS/MVS), that automatically
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 Multi-Processing
(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 link (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.
hop Interswitch connection. A hop count is the
number of connections that a particular
block of data traverses between source
and destination. For example, data
traveling from one hub over a wire to
another hub traverses one hop.
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DS6000 Host Systems Attachment Guide