3PAR InForm® OS 2.2.4 Concepts Guide (320-200085 Rev B, March 2009)

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Glossary
InForm OS Version 2.2.4 3PAR InForm OS Concepts Guide
child volume
A virtual volume (virtual or physical copy) made
from a parent volume.
chunklet
A 256-MB block of contiguous space on a
physical disk.
chunklet logging
An action by the system that occurs when a
chunklet is unavailable (for example, the disk is
not ready). The chunklet is placed in logging
mode, where data that is supposed to be written
to the chunklet is instead written to a log. If the
chunklet becomes available again, the system
places the chunklet in playback mode, where the
data is read from the log and written to the
appropriate chunklet.
classes of service
The characteristics and guarantees of the
transport layer of a Fibre Channel circuit. These
classes include connection services (Class 1),
guaranteed frame delivery with end-to-end flow
control (Class 2), and packetized frame
datagrams (Class 3).
clean chunklet
A chunklet that is set to all zeros, and therefore
does not contain any data.
cluster
A group of controller nodes connected via the
same storage server backplane. The nodes in a
cluster operate as a unified system, separate
from any other clusters that may share the same
service processor.
CMP
See cache memory page.
common provisioning group (CPG)
A set of logical disks from which you can create
virtual volumes and virtual copies that are
capable of allocating storage on demand.
component indicator
InForm Management Console alert pane icon
that represents a logical or physical storage
server component. See also alert pane.
control cache
Memory modules that support the
microprocessors located in a controller node.
control cache DIMM
A single control cache memory module.
controller node
An individual device that works together with
other controller nodes to cache and manage
data in a storage server and to provide hosts
with a coherent, virtualized view of the storage.
controller node chassis
An enclosure that houses all the controller nodes
of a storage server.
copy-on-write snapshot
A snapshot of a virtual volume made with the
copy-on-write technique. Consists of a pointer to
the source volume and a record of every change
made to the source volume since the snapshot
was created.
Commonly Provisioned Virtual Volume (CPVV)
A virtual volume with a set amount of user
space and whose snapshot administration
space and snapshot data space draw from a
common provisioning group (CPG).