HP SAN Virtualization Services Platform - Manual (Page 89)

HBA See host bus adapter .
host In VSM, every server that uses VSM virtual disks. Servers that run as VSM servers
are also considered hosts.
host bus adapter A device that provides input/output (I/O) processing and physical connectivity
between a server and a storage system. In order to minimize the impact on host
processor performance, the host bus adapter performs many low-level interface
functions automatically or with minimal processor involvement.
I/O Input/Output. Data transferred from one device to another.
in use path A path that is currently being used for I/O traffic.
See also
active path .
inactive boot set The boot set that is not in use in a running system. Applies to the DPM.
initiator See initiator device .
initiator device A device, such as an HBA installed into a server, that contains one or more
initiator ports.
initiator port A Fibre Channel port capable of issuing new SCSI commands over Fibre Channel
(FCP) commands.
invalid boot set A boot set that is empty or otherwise does not contain a usable system image.
iSCSI Internet Small Computer System Interface. An IP-based standard for transferring
data by carrying SCSI commands over IP networks (by encapsulating SCSI data
in TCP packets).
kdisk A path from a virtual disk presentation on the DPM front side to a server. For
example, there is one kdisk per virtual disk for each unique server initiator
port–to–DPM target port combination.
LBA Logical Block Addressing. The addressing mode used for reading from or writing
to a specific sector on a back-end LU. Early PC hard drives specified the sector
in terms of its cylinder number, its head number, and its sector number. LBA
addressing uses just one number. In LBA addressing, the first sector on the
back-end LU is sector zero and all sectors on the back-end LU are simply
incremented from there. Also known as the Logical Block Number (LBN).
LUN Logical Unit Number. A unit of storage that a storage system presents to the SAN
and shows up as a back-end LU when presented to servers. Every storage system
can usually expose multiple logical units, each having a unique number (Logical
Unit Number), which allows servers to access that particular logical unit. LUNs
that a storage system exposes to the SVSP domain are identified by VSM as
back-end LUs.
migration A VSM service that migrates virtual disks from one storage pool to another while
the host application remains online.
mirror A VSM service that mirrors virtual disks synchronously and asynchronously.
See also
asynchronous mirroring and synchronous mirroring .
mirroring The creation and continuous updating of one or more redundant copies of data,
usually for the sake of fault or disaster recovery.
HP StorageWorks SAN Virtualization Services Platform Data Path Module user guide 89