EMC Symmetrix DMX-3 Product Manual page 310

Glossary
backplane
business continuance
volumes (BCVs)
cache slot
channel director
CCOPY
command descriptor
block (CDB)
Compatible Parallel
Access Volumes
(COM-PAV)
controller ID
Count-Key-Data
310 EMC Symmetrix DMX-3 Product Guide
B
Card that accommodates the channel directors, disk directors, global
memory directors, channel adapters, and the XCM.
bit
The smallest unit of computer memory. A bit can hold a value of zero
or one.
A standard Symmetrix device with special attributes that allow it to
independently support applications and processes, such as backup
operations, restore operations, Decision Support operations, and
application testing. BCV devices are available through the EMC
TimeFinder software.
byte Any 8-bit unit of data storage.
C
cache
See Global Memory.
Unit of cache equivalent to one track.
The component in the Symmetrix subsystem that interfaces between
the host channels and data storage. It transfers data between the
channel and global memory.
Concurrent Copy Facility used on IBM DASD.
The structure used to communicate commands from an initiator to a
target. This structure may be 6 bytes, 10 bytes, or 12 bytes in size.
Compatible Parallel Access Volumes is an IBM feature, supported by
the Symmetrix unit, that improves response time, resulting in greater
resource availability to the host.
Controller identification number of the director that the disks are
channeled to for EREP usage. There is only one controller ID for the
Symmetrix unit.
A data recording format employing self-defining record formats in
(CKD) which each record is represented by a count area that identifies the
record and specifies its format, an optional key area that may be used
to identify the data area contents, and a data area that contains the
user data for the record. CKD can also refer to a set of channel