Avago Technologies AcceleRAID 170LP - Manual (Page 81)

Glossary
Manual No. DB11-000024-00 G-23
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.
RS-232C
Recommended Standard-232 revision C, a long-established standard that
describes the physical interface and protocol for relatively low-speed serial
data communication between computers and related devices. RS-232C is the
interface that a computer uses to talk to and exchange data with your modem
and other serial devices. It is an asynchronous 9 or 25-pin connector.
RS 422/423
Recommended Standard 422/423, a 32-pin serial connector that can be used
for either synchronous or asynchronous transmission of data. The 422 is a
differential line; the 423 is a single line.
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,
operating systems, server platforms, and RAID implementation because the
enclosure itself is treated as simply another device on the SCSI bus. Many
other leading server, storage, and RAID controller manufacturers worldwide