IBM E16RMLL-I - Tivoli Storage Manager, Implementation Manual

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Glossary
753
Host Any system that has at least one
Internet address associated with it. A host with
multiple network interfaces can have multiple
Internet addresses associated with it. This is
also referred to as a server.
Host bus adapter (HBA) A Fibre Channel
HBA connection that allows a workstation to
attach to the SAN network.
Hub A Fibre Channel device that connects
up to 126 nodes into a logical loop. All
connected nodes share the bandwidth of this
one logical loop. Hubs automatically recognize
an active node and insert the node into the
loop. A node that fails or is powered off is
automatically removed from the loop.
IP Internet protocol.
J
Java A programming language that enables
application developers to create
object-oriented programs that are very secure,
portable across different machine and
operating system platforms, and dynamic
enough to allow expandability.
Java runtime environment (JRE™) The
underlying, invisible system on your computer
that runs applets the browser passes to it.
Java Virtual Machine (JVM™) The
execution environment within which Java
programs run. The Java virtual machine is
described by the Java Machine Specification,
which is published by Sun Microsystems.
Because the Tivoli Kernel Services is based
on Java, nearly all ORB and component
functions execute in a Java virtual machine.
JBOD Just a Bunch Of Disks.
JRE See Java runtime environment.
JVM See Java Virtual Machine.
L
Logical unit number (LUN) The LUNs are
provided by the storage devices attached to
the SAN. This number provides you with a
volume identifier that is unique among all
storage servers. The LUN is synonymous with
a physical disk drive or a SCSI device. For
disk subsystems such as the IBM Enterprise
Storage Server, a LUN is a logical disk drive.
This is a unit of storage on the SAN that is
available for assignment or unassignment to a
host server.
Loop topology In a loop topology, the
available bandwidth is shared with all the
nodes connected to the loop. If a node fails or
is not powered on, the loop is out of operation.
This can be corrected using a hub. A hub
opens the loop when a new node is connected
and closes it when a node disconnects. See
also Fibre Channel Arbitrated Loop and
arbitrated loop.
LUN See logical unit number.
LUN assignment criteria The combination
of a set of LUN types, a minimum size, and a
maximum size used for selecting a LUN for
automatic assignment.
LUN masking This allows or blocks access
to the storage devices on the SAN. Intelligent
disk subsystems like the IBM Enterprise
Storage Server provide this kind of masking.
M
Managed object A managed resource.