R-S

RAID

Redundant Arrays of Inexpensive Disks; a term that refers to the method of writing the same data to several disks at the same time to offer fault tolerance in case of data loss.

RARP

A protocol to resolve the hardware address of a machine to its IP address; opposite of ARP.

RBAC

Role-based access control; a security model for controlling user access to tasks that will normally be restricted to the superuser. The RBAC model offers a more secure and flexible alternative to the superuser model by assigning security rights to what is called a role and then assigning the role to a user.

reboot

A command that synchronizes the file systems and initiates a multiuser reboot.

Redundant Arrays of Inexpensive Disks

See RAID.

repeater

A device that can be used to amplify or to repeat an existing signal.

Reverse Address Resolution Protocol

See RARP.

rlogin

A command used to establish a remote login session from a local console.

rm

A command used to delete files and directories.

rmdir

A command used to delete a directory.

role-based access control

See RBAC.

router

An Internet device that receives a frame from a computer (or another router), retrieves the datagram from the frame, figures out (possibly with the help of the routing table) the next recipient, which may be a local host or the next hop router, puts it into a new frame, and sends it.

rule

A statement that uses a set of system attributes to identify a group of machines and links it to a profile file. You define the rules in a text file whose name must be rules. Before JumpStart can use the rules file and the profiles, you need to perform a validation by running the check script. This script verifies that the rules in the rules file and the associated profiles are set up correctly, and if they are, the script creates the rules.ok file, the file that is actually used by the JumpStart program.

rules.okfile

See rule.

run level

The state of a system denoted by a digit or a letter. The Solaris system always runs in one of a set of well-defined run levels.

Scalable Processor Architecture (SPARC)

A term that refers to Sun Microsystems' proprietary processor design.

server

A host and an application running on the host that accepts a request from a client and serves the request.

service instance

A service running with a specific configuration. A service may have more than one instance, and a service is managed by SMF by its instance name: FMRI.

service management facility

An infrastructure that augments the traditional UNIX startup scripts, init run levels, and configuration files to make the service management more robust.

shell

The interface between the user (or an application) and the kernel. The shell interprets the commands from the user for the kernel.

shutdown

A command that calls the init program to shut down the system; the default target run level is S.

signal

A message sent to a process in order to affect its operation. Solaris supports the concept of communicating with a process by sending it a signal.

Simple Mail Transfer Protocol

A TCP/IP protocol used by mail servers to exchange messages over the Internet.

SMC

See Solaris Management Console.

SMTP

See Simple Mail Transfer Protocol.

software group

A grouping of software packages and clusters. During initial installation of Solaris, you select a software group to install based on the functions you want your system to perform.

Solaris Management Console

A graphical user interface (GUI) utility to access a set of administrative tools.

Solaris Volume Manager

A software product used to manage huge amounts of data spread over a large number of disks.

Solaris zone

A virtual operating system environment created by one instance of the Solaris operating system. There may be more than one zone on the same machine, and processes running in one zone cannot monitor or affect processes running in other zones. Processes running in different zones can only interact with each other through network APIs.

SPARC

See Scalable Processor Architecture (SPARC).

state database

A database that contains the configuration and status information about the disk sets, volumes, and hot spares in a disk set managed by the SVM.

sticky bit

A permission set used to ensure that a file can only be deleted by its owner.

Stop-A

The keyboard combination used to bring a system to the PROM console: the ok prompt.

striping

A process that breaks the data into small pieces called stripes, which are written to multiple disks simultaneously. Because the read/write heads are working simultaneously, striping improves read/write performance.

superblock

The area of a disk that contains the file system information.

SVM

See Solaris Volume Manager.

swap

A command used to monitor the swap space.

swapfs (SWAPFS)

A virtual file system that manages the swap space.

swap space

The disk slices, also called swap slices, used for storing virtual memory.

switch

A network device such as a hub, but unlike a hub, a switch is aware of the MAC addresses of the computers connected to it and repeats a received signal only on a port to which the intended recipient of the data is connected.

symbolic link

An indirect pointer to a file; that is, its directory entry contains the name of the file to which it points. Furthermore, it may span file systems and may point to either a directory or a file.

syslog

The system message logging that automatically saves (logs) various system errors and warnings in the message files.