IBM DS8000 User Manual page 220

disk drive
Standard term for a disk-based
nonvolatile storage medium. The DS8000
series use hard disk drives as the primary
nonvolatile storage media to store host
data.
disk drive module (DDM)
A field replaceable unit that consists of a
single disk drive and its associated
packaging.
disk drive module group
See disk pack.
disk drive set
A specific number of identical disk drives
that have the same physical capacity and
rpm.
disk pack
A group of disk drive modules (DDMs)
installed as a unit in a DDM bay.
disk group
A collection of 4 disk drives that are
connected to the same pair of IBM Serial
Storage adapters and can be used to
create a RAID array. A disk group can be
formatted as count key data or fixed
block, and as RAID or non-RAID, or it
can be left unformatted. A disk group is a
logical assemblage of disk drives.
Contrast with disk pack.
distributed file service (DFS)
A service that provides data access over
IP networks.
DNS See domain name system.
domain
1) That part of a computer network in
which the data processing resources are
under common control.
2) In TCP/IP, the naming system used in
hierarchical networks.
domain name system (DNS)
In TCP/IP, the server program that
supplies name-to-address translation by
mapping domain names to internet
addresses. The address of a DNS server is
the internet address of the server that
hosts the DNS software for the network.
dotted decimal notation
A convention used to identify IP
addresses. The notation consists of four
8-bit numbers written in base 10. For
192
DS8000 User's Guide
example, 9.113.76.250 is an IP address
that contains the octets 9, 113, 76, and 250.
drawer
A unit that contains multiple device drive
modules and provides power, cooling,
and related interconnection logic to make
the device drive modules accessible to
attached host systems.
drive 1) A peripheral device, especially one that
has addressed storage media. See also disk
drive module.
2) The mechanism used to seek, read, and
write information on a storage medium.
DS8000 series
See IBM System Storage DS8000.
DS8000 Batch Configuration tool
A program that automatically configures a
DS8000 storage unit. The configuration is
based on data that IBM service personnel
enter into the program.
DS Storage Manager
See IBM System Storage DS Storage
Manager.
duplex
1) Regarding Copy Services, the state of a
volume pair after Remote Mirror and
Copy has completed the copy operation
and the volume pair is synchronized.
2) In general, pertaining to a
communication mode in which data can
be sent and received at the same time.
dynamic sparing
The ability of a storage server to move
data from a failing disk drive module
(DDM) to a spare DDM while
maintaining storage functions.
E
E10 The predecessor of the F10 model of the
Enterprise Storage Server. See also F10.
E20 The predecessor of the F20 model of the
Enterprise Storage Server. See also F20.
EC See engineering change.
™
ECKD
See extended count key data.
eight pack
See disk pack.