Sun Microsystems Fire X4540, Руководство администратора

Страница: 151 / 154

Glossary 137
unshielded twisted
pair/shielded twisted
pair (UTP/STP) A type of Ethernet cable.
user account A record of essential user information that is stored on the system. Each user
who accesses a system has a user account.
User Datagram Protocol
(UDP) A connectionless, transport layer protocol that adds some reliability and
multiplexing to the Internet Protocol (IP). UDP enables one application
program to deliver, via IP, datagrams to another application program on
another machine. The Simple Network Management Protocol (SNMP) is
usually implemented over UDP.
user identification
(userid) A unique string identifying a user to a system.
user identification
number (UID
number) The number assigned to each user accessing a UNIX system. The system uses
UID numbers to identify, by number, the owners of files and directories.
user name A unique combination of letters, and possibly numbers, that identifies a user to
the system.
V
voltage regulator
module (VRM) An electronic device that regulates a system’s microprocessor voltage
requirements in order to maintain the correct voltage.
volume One or more drives that can be grouped into a unit for data storage. Also
called a logical unit or LUN.
volume manager Software that organizes data blocks on physical disk drives into logical
volumes, which makes the disk data independent of the physical path name of
the disk drives. Volume manager software provides data reliability through
disk striping, concatenation, mirroring, and dynamic growth of metadevices or
volumes.