Mylex Global Array Manager Installation Manual And User's Manual page 196

Glossary
replaced by others through standby replacement.
ROM
Read-Only Memory, built-in computer memory containing data that
normally can only be read, not written to. ROM contains the programming
that allows a computer to be "booted up" each time you turn it on. Unlike a
computer's random access memory (RAM), the data in ROM is not lost when
the computer power is turned off; the ROM is sustained by a small long-life
battery in your computer.
Rotated XOR Redundancy
XOR refers to the Boolean "Exclusive-OR" operator. Also known as Parity, a
method of providing complete data redundancy while requiring only a
fraction of the storage capacity of mirroring. In a system configured under
RAID 3 or RAID 5 (which require at least three SCSI drives), all data and
parity blocks are divided amongst the drives in such a way that if any single
drive is removed (or fails), the data on it can be reconstructed using the data
on the remaining drives. In any RAID 3 or RAID 5 array, the capacity
allocated to redundancy is the equivalent of one drive.
RTC
Real-Time Clock, a clock that keeps track of the time with its own power
supply.
SAF-TE
SCSI Accessed Fault-Tolerant Enclosure, an "open" specification designed
to provide a comprehensive standardized method to monitor and report
status information on the condition of disk drives, power supplies, and
cooling systems used in high availability LAN servers and storage
subsystems. The specification is independent of hardware I/O cabling,
Glossary-20 GAM Client User's Guide