2 December 1999
PFC 500/E Instruction Manual
73
PLDA (private loop direct attach) profile — A standard for FC-AL disk drives.
RAID controller (RC) — See RC (RAID controller).
RC (RAID controller) — A printed-circuit board with memory modules and control
logic that manages the storage-system I/O between the Profile XP Media Platform
FC adapter and the disk modules. The RC in a PFC500/E storage system sends the
multiplexed fibre channel loop traffic through a link control card (LCC) to the disk
units. For higher availability, a PFC500 can use a second RC.
RC memory module — A memory module (DIMM or SIMM) that provides the
local storage for an RC.
replace under power — The storage system provides replace under power
capability, allowing you to replace, for example, a disk module or a fan module
without powering down the storage system. Applications continue while you replace
the failed module.
SCSI (small computer system interface) — A well-known protocol and standard
for connecting computers and peripheral devices.
SES (SCSI enclosure services) — A functional subset of SCSI III commands that
allow a server to communicate with storage enclosures using their disk modules.
SFF — Small Form Factor Committee
server — In the context of storage systems, a processor that runs an operating
system and uses a disk-array storage system for data storage and retrieval.
storage chassis — A storage device that includes a chassis, up to 10 disk modules,
one or two Fibre Channel LCCs, and one or two power supplies.
storage-system caching — The procedure of storing disk-based data in RAM
memory (in this case, DIMM memory on an RC) temporarily to save time if the data
needs to be accessed or changed again soon.
