HP StorageWorks SAN Virtualization Services Platform Data Path Module User Guide (5697-0772, November 2010)

synchronous
mirroring
A mode of data mirroring in which the updates on the mirror site are synchronized
between destinations.
system software
image
A software component, capable of being updated, that contains the operating
environment for the Data Path Module, including the SVSP VSM agent for the
Data Path Module.
target Receives commands from the initiator, and after execution, returns
acknowledgement to the initiator.
See also initiator.
target device A device that contains one or more target ports.
target port A Fibre Channel port capable of presenting one or more SCSI LUNs to servers.
A target is also known as the destination of a server's I/O request.
task In VSM, a process that carries out a data moving task on a group.
temporary virtual
disk
A virtual disk created when a PiT is created on another virtual disk. The temporary
virtual disk holds any modifications redirected from the original virtual disk after
the PiT is created.
thick provisioned A quality of virtual disks wherein the virtual disk’s allocated capacity is always
equal to its total capacity.
See also virtual disk.
thin provisioned A quality of virtual disks wherein the virtual disk’s allocated capacity is set to a
small initial value that can expand up to the virtual disk’s total capacity according
to actual usage.
transaction
consistent
The state of the media behind a logical unit, such that all pending writes have
been completed, and all caches are empty.
transceiver A device that provides an interface between the Data Path Module hardware
and the external network cable. The Data Path Module uses 4–Gbps optical
small form-factor pluggable transceivers.
trunk A group of interswitch links (ISLs) configured to work together to connect two
Fibre Channel switches with a higher bandwidth than a single ISL. Each trunk is
treated as a single path for the switch to route I/O destined for a device on the
other switch.
UDH User defined hosts are all servers other than the VSM servers that are attached
to the SVSP domain.
valid boot set A DPM boot set that contains a usable system image.
VDG Virtual Disk Group. A single entity that encapsulates multiple virtual disks or
snapshots to enable synchronized operations on the members.
virtual disk In VSM, a unit of storage allocated to one or more hosts from a storage pool. A
virtual disk can range in size from 1 GB to 2 TB. DPMs present allocated virtual
disks to hosts as logical drives.
VMA Virtualization Management Appliance.
Glossary92