Technical data

GL–13
Compaq HSG80 Array Controller ACS Version 8.3 Maintenance and Service Guide
port (1) In general terms, a logical channel in a communications system. (2) The
hardware and software used to connect a host controller to a
communications bus, such as a SCSI bus or serial bus.
Regarding the controller, the port is (1) the logical route for data in and out
of a controller that can contain one or more channels, all of which contain
the same type of data. (2) The hardware and software that connects a
controller to a SCSI device.
primary cabinet The primary cabinet is the subsystem enclosure that contains the controllers,
cache modules, external cache batteries, and the PVA module.
program card The PCMCIA card containing the controller’s operating software.
protocol The conventions or rules for the format and timing of messages sent and
received.
PTL Port-Target-LUN. The controller’s method of locating a device on the
controller’s device bus.
PVA module Power Verification and Addressing module.
quiesce The act of rendering bus activity inactive or dormant. For example, “quiesce
the SCSI bus operations during a device warm-swap.”
RAID Redundant Array of Independent Disks. Represents multiple levels of
storage access developed to improve performance or availability or both.
RAID level 0 A RAID storageset that stripes data across an array of disk drives. A single
logical disk spans multiple physical disks, allowing parallel data processing
for increased I/O performance. While the performance characteristics of
RAID level 0 is excellent, this RAID level is the only one that does not
provide redundancy. Raid level 0 storagesets are sometimes referred to as
stripesets.
RAID level 0+1 A RAID storageset that stripes data across an array of disks (RAID level 0)
and mirrors the striped data (RAID level 1) to provide high I/O performance
and high availability. This RAID level is alternatively called a striped
mirrorset. Raid level 0+1 storagesets are sometimes referred to as striped
mirrorsets.