DEC 4000 600 series Owner's Manual page 226

program mode
See operating system mode.
R400X mass storage expander
A Digital enclosure used for mass storage expansion.
RAID
Redundant array of inexpensive disks. A technique that
organizes disk data to improve performance and reliability.
RAID has three attributes:
1. It is a set of physical disks viewed by the user as a single
2. The user's data is distributed across the physical set of
3. Redundant disk capacity is added so that the user's data can
Contrast with striping.
reliability
The probability a device or system will not fail to perform
its intended functions during a specified time interval when
operated under stated conditions.
remote access device
Hardware other than the local console terminal that can access a
system's console user interface. The remote device is connected
to the system through the system's auxiliary serial port or
Ethernet.
removable-media compartment
Compartment in the enclosure that houses removable media.
RISC
Reduced instruction set computer. A computer with an
instruction set that is reduced in complexity.
Glossary–10
logical device.
drives in a defined manner.
be recovered even if a drive fails.