Sun Microsystems Sun Fire X4150 - Manual (Page 140)

124 Sun Fire X4150 Server Embedded Lights Out Manager Administration Guide • September 2007
programmable read-
only memory
(PROM) A memory chip on which data can be programmed only once and which
retains the program forever. PROMs retain data even when power is off.
protocol A set of rules that describes how systems or devices on a network exchange
information.
proxy A mechanism whereby one system acts on behalf of another system in
responding to protocol requests.
public key encryption A cryptographic method that uses a two-part key (code) that is made up of
public and private components. To encrypt messages, the published public
keys of the recipients are used. To decrypt messages, the recipients use their
unpublished private keys, which are known only to them. Knowing the public
key does not enable users to deduce the corresponding private key.
R
rack unit (U) A measure of vertical rack space equal to 1.75 inches (4.45 cm).
random access memory
(RAM) Volatile, semiconductor-based memory in which any byte of memory can be
accessed without touching the preceding bytes.
read-only file A file that a user cannot modify or delete.
read-only memory
(ROM) A nonvolatile memory chip on which data has been prerecorded. Once written
onto a ROM chip, data cannot be removed and can only be read.
real-time clock (RTC) A battery-backed component that maintains the time and date for a system,
even when the system is powered off.
reboot An operating system–level operation that performs a system shutdown
followed by a system boot. Power is a prerequisite.
Red Hat Package
Manager (RPM) A collection of tools developed by Red Hat, Inc. for Red Hat Linux that can
automate the install, uninstall, update, verify, and query software processes on
a computer. RPM is now commonly used by many Linux vendors.
redirection The channeling of input or output to a file or device rather than to the standard
input or output of a system. The result of redirection sends input or output
that a system would normally display to the display of another system.