Specifications

Glossary GL–3
block Also called a sector. The smallest collection of consecutive bytes addressable
on a disk drive. In integrated storage elements, a block contains 512 bytes of
data, error codes, flags, and the block’s address header.
bootstrapping A method used to bring a system or device into a defined state by means of its
own action. For example, a machine routine whose first few instructions are
enough to bring the rest of the routine into the computer from an input device.
built-in self-test A diagnostic test performed by the array controller software on the
controller’s policy processor.
byte A binary character string made up of 8 bits operated on as a unit.
cache memory A portion of memory used to accelerate read and write operations.
CCITT Acronym for Consultive Committee International Telephone and Telegraph.
An international association that sets worldwide communication standards,
recently renamed International Telecommunications Union (ITU).
CDU Cable distribution unit. The power entry device for STORAGEWORKS
cabinets. The CDU provides the connections necessary to distribute power to
the cabinet shelves and fans.
channel An interface which allows high speed transfer of large amounts of data.
Another term for a SCSI bus.
See also SCSI.
chunk A block of data written by the host.
chunk size The number of data blocks, assigned by a system administrator, written to the
primary RAIDset or stripeset member before the remaining data blocks are
written to the next RAIDset or stripeset member.
CLCP An abbreviation for code-load code-patch utility.
CLI See command line interpreter.
coax See coaxial cable.
coaxial cable A two-conductor wire in which one conductor completely wraps the other
with the two separated by insulation.
cold swap A method of device replacement that requires the entire subsystem to be
turned off before the device can be replaced.
See also hot swap and warm swap.