Glossary

S

S/390 mode

The mode that is most useful when attaching to IBM S/390 Enterprise Servers. See also open systems mode; operating mode.

SA/MVS™

See System Automation for Operating System/390.

SAN

See storage area network; system area network.

SA OS/390™

See System Automation for Operating System/390.

scalable

Refers to how well a system can adapt to increased demands. For example, a scalable network system could start with just a few nodes but easily expands to thousands of nodes. Scalability is important because it allows the user to invest in a system with confidence that a business will not outgrow it. Refers to anything whose size can be changed.

SCSI

See small computer system interface.

segment

A fabric segments when one or more switches cannot join the fabric because of various reasons. The switch or switches remain as separate fabrics.

segmented E_Port

See segmented expansion port.

segmented expansion port

Segmented E_Port. E_Port that has ceased to function as an E_Port within a multiswitch fabric due to an incompatibility between the fabrics that it joins. See also bridge port; fabric port; generic port; node port.

serial port

A full-duplex channel that sends and receives data at the same time. It consists of three wires: two that move data one bit at a time in opposite directions, and a third wire that is a common signal ground wire.

server

A computer that provides shared resources, such as files and printers, to the network. Used primarily to store data, providing access to shared resources. Usually contains a network operating system.