IBM L5U, Maintenance Information

Page: 285 / 295

Glossary
D-7
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.
reboot . Restart the library.
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.
RML . Rack Mount Line.
robot . Picker.
robotics . Picker 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.
scratch cartridge . A data cartridge that contains no
useful data, but can be written to with new data.
SCSI . Small computer system interface.
segment . A part.
sel . Select.
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.
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.
• SCSI-2: Same as SCSI-1, but uses a 50-pin connector
instead of a 25-pin connector, and supports multiple
devices.
• Ultra SCSI: Uses an 8- or 16-bit bus, and supports data
rates of 20 or 40 MBps.
• Ultra2 SCSI: Uses an 8- or 16-bit bus and supports
data rates of 40 or 80 MBps.
• Ultra3 SCSI: Uses a 16-bit bus and supports data rates
of 80 or 160 MBps.
• Ultra160 SCSI: Uses a 16-bit bus and supports data
rates of 80 or 160 MBps.
SNMP . Simple Network Management Protocol. Used
by network management systems to monitor
network-attached devices.
SNS . Sense.
SNTP . Simple Network Time Protocol. Used to
synchronize the clocks of network-attached devices.
special feature . A feature that can be ordered to
enhance the capability, storage capacity, or performance
of a product, but is not essential for its basic work.
SPI . Security Parameters Index.