IBM System Storage TS2900, Setup, Operator, And Service Manual

Page: 246 / 257

I-8
TS2900 Tape Autoloader Setup, Operator, and Service Guide
PTF . Program temporary fix. A single bugfix or group
of bugfixes distributed in a form ready to install for
customers.
PWR . Power.
R
rack . A unit that houses the components of a storage
subsystem, such as the library.
rackmount kit . A packaged collection of articles used
to install the rack mounted version of the library.
RAM . Random access memory.
random access memory . A storage device into which
data is entered and from which data is retrieved in a
nonsequential manner.
RAS . Reliability, availability, and serviceability.
record . A collection of related data or words, treated as
a unit.
recording density . The number of bits in a single linear
track measured per unit of length of the recording
medium.
recoverable error . An error condition that allows
continued execution of a program.
ref . Reference.
reg . Register.
reinventory . To inventory again.
retension . The process or function of tightening the
tape onto the cartridge, if it is sensed that the tape has a
loose wrap on the cartridge.
RFC (Request for Comments) . Request for Comments
(RFC) documents are a series of memoranda
encompassing new research, innovations, and
methodologies applicable to Internet technologies.
RH . Relative humidity.
RML . Rack Mount Line.
robot . Accessor.
robotics . Accessor assembly.
root CA certification . In cryptography, a root
certificate from a Certificate Authority (CA).
RPQ . Request for price quotation.
RSA key . Encryption key type.
R/W . Read/write.
S
s . Seconds of time.
SAC . Service Action Code. Code developed to indicate
possible FRU or FRUs to replace to repair the hardware.
SAS. See
Serial Attached SCSI .
scratch cartridge . A data cartridge that contains no
useful data, but can be written to with new data.
SCSI . Small computer system interface.
SE . Single-ended.
segment . A part.
sel . Select.
Serial Attached SCSI (SAS) . A drive with a SAS
interface can be linked directly to controllers. SAS is a
performance improvement over traditional SCSI because
SAS enables multiple devices (up to 128) of different
sizes and types to be connected simultaneously with
thinner and longer cables. It supports full-duplex signal
transmission up to 3 Gb/s. In addition, SAS drives can
be hot-plugged.
serialize . To change from parallel-by-byte to
serial-by-bit.
serializer . A device that converts a space distribution
of simultaneous states representing data into a
corresponding time sequence of states.
servo, servos . An adjective for use in qualifying some
part or aspect of a servomechanism.
servomechanism . A feedback control system in which
at least one of the system signals represents mechanical
motion.
signature . A digital signature used in cryptography to
identify one party to ensure authenticity.
slot blocker . A slot blocker is used to restrict/close off
a data cell so a data cartridge cannot be inserted.
Small Computer Systems Interface (SCSI) . A
standard used by computer manufacturers for attaching
peripheral devices (such as tape drives, hard disks,
CD-ROM players, printers, and scanners) to computers
(servers). Pronounced “scuzzy”. Variations of the SCSI
interface provide for faster data transmission rates than
standard serial and parallel ports (up to 160 megabytes
per second). The variations include:
• Fast/Wide SCSI: Uses a 16-bit bus, and supports data
rates of up to 20 MBps.
• SCSI-1: Uses an 8-bit bus, and supports data rates of 4
MBps.