Glossary - IBM TotalStorage DS300 Best Practices Manual

Glossary

A
Agent A software entity that runs on endpoints
and provides management capability for other
hardware or software. An example is an SNMP
agent. An agent has the ability to spawn other
processes.
AL See arbitrated loop.
Allocated storage The space that is allocated to
volumes, but not assigned.
Allocation The entire process of obtaining a
volume and unit of external storage, and setting
aside space on that storage for a data set.
Arbitrated loop A Fibre Channel interconnection
technology that allows up to 126 participating node
ports and one participating fabric port to
communicate. See also Fibre Channel Arbitrated
Loop and loop topology.
Arbitration The process of selecting one
respondent from a collection of several candidates
that request service concurrently.
© Copyright IBM Corp. 2006. All rights reserved.
Address Resolution Protocol (ARP) ARP is a
layer 3 protocol and is required to allow a sending
station to gather address information used in
forming a layer 2 frame complete with destination
and source MAC addresses. Every router maintains
a table listing IP addresses and respective hardware
addresses (e.g. MAC addresses) of devices that
exist on the network. This table is called an ARP
cache and is referenced by the router when it is
looking up a hardware address of a device for which
it knows the IP address and needs to forward a
datagram to it. If no hardware address is found in the
ARP cache then an ARP broadcast is sent on to the
adjoining media (ARP only applies to the connecting
wire). This broadcast is read by every station
including the destination station. The destination
station sends back an ARP reply with its hardware
address so that the IP datagram can now be
forwarded to it by the router.
Array An arrangement of related disk drive
modules that have been assigned to a group.
B
Backup A copy of computer data that is used to
recreate data that has been lost, mislaid, corrupted,
or erased. The act of creating a copy of computer
data that can be used to recreate data that has been
lost, mislaid, corrupted or erased.
Bandwidth A measure of the data transfer rate of
a transmission channel.
BCP See Business Continuity planning
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