Glossary - HP MPIO Installation And Reference Manual

Glossary

This glossary defines the terms used in this guide or related to this product. It is not a comprehensive
glossary of computer terms.
ALB
controller
DSM
fabric
failover
HBA
host
LUN
mode
MPIO
path
path state
Adaptive Load Balance (ALB) is a feature provided by the EVA DSM that utilizes
certain features supported by the array, to deliver better performance for host
I/O requests.
A hardware device that facilitates communication between a host and one
or more LUNs organized as an array.
Device Specific Module
A network that contains high-speed fiber connections resulting from the
interconnection of switches and devices. A fabric is an active and intelligent
non-shared interconnect scheme for nodes.
The automatic substitution of a functionally equivalent system component for
a component that has failed.
Host Bus Adapter. An I/O device that serves as the interface connecting a host
system to the SCSI bus or SAN (Storage Area Network)
The computer system on which the Multipath software is running.
Logical Unit Number. The actual unit number assigned to a device by the RAID
system controller.
A user-selectable parameter that specifies path behavior during normal and
failure conditions. Paths can be set to one of the following modes:
• Preferred — Indicates the path you choose for the desired I/O paths. When
a path is in preferred mode, load balance is not enabled and the Load
Balance Type displays as none.
• Alternate — Indicates a path that is used for device access and I/O activities
when the preferred path fails.
Multipathing Input/Output.
A virtual communication route that enables data and commands to pass
between a host server and a storage device.
An attribute that describes the operational condition of a path. A path can exist
in one of the following states:
• Active — Path is currently used for the I/O stream or is available for load
balancing.
• Available — Path is currently available, but not used for device access. The
path is only in this state when no load balancing policy has been selected
for the LUN.
• Standby — Intermediate state of the path before it is initialized (made ready
for device access), normally will not be seen.
• Failed — Path is currently unusable for the I/O stream.
HP MPIO Full Featured DSM for EVA4x00/6x00/8x00 family of Disk Arrays 3.00.00
51