HP SAN Virtualization Services Platform - Manual (Page 73)

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.
interswitch link
(ISL) A connection between two Fibre Channel switches that creates a single switch fabric. Multiple
physical connections between the same two Fibre Channel switches create multiple ISLs. Each
independent ISL is treated as a single path between the two switches.
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).
K
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.
L
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.
M
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.
O
OpenVMS Unit ID Abbreviated as OUID. A storage element identifier that is necessary for hosts running OpenVMS
to interact with the storage elements presented to them. This identifier is relevant to virtual disks,
snapshots, and synchronous mirror groups.
P
passive path A path that must have some operation (for example, a SCSI start unit command that is issued by
the server) performed on it to make it active.
See also active/active RAID, active/passive RAID, and secondary path..
patch file Incremental update to an existing system image.
persistent
reservation A mechanism for the resolution of dynamic SCSI contention in systems with multiple initiator ports
accessing a logical unit, whereby a single initiator port or a set of initiator ports can reserve the
logical unit indefinitely. While reserved, the storage device server rejects all commands for that
logical unit from any other initiator ports.
personality The way in which a DPM exposes LUNs to the hosts that use them. Exposing a LUN with the
correct personality (such as HP EVA VS-ALUA or HP EVA MS-DPM) for the hosts enables features
such as failover and failback between DPMs in conjunction with the appropriate multipath software
running on the host. See the HP StorageWorks SAN Virtualization Services Platform Manager
User Guide for a list of personalities used with SVSP.
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