Sun Microsystems Fire X4540, Руководство администратора

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132 Sun Fire X4500/ X4540 Servers Administration Guide • October 2008
power-on self-test
(POST) A program that takes uninitialized system hardware and probes and tests its
components at system startup. POST configures useful components into a
coherent, initialized system and hands it over to the OpenBoot PROM. POST
passes to OpenBoot PROM a list of only those components that have been
successfully tested.
PowerPC An embedded processor.
Q
quiesce To halt all drive activity.
R
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.
read caching Data stored for future retrieval, to reduce disk I/O as much as possible.
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.
redundant array of
independent disks
(RAID) A configuration in which multiple drives are combined into a single virtual
drive to improve performance and reliability.
reliability, availability,
and serviceability
(RAS) A term to describe product features that include high availability, easily
serviced components, and dependability.