IBM 201 manual FIC see File Image Capture, FIR see File Image Restore

FIC (see File Image Capture).

Field-replaceable unit (FRU). An assembly that is replaced in its entirety when any one of its components fails. In some cases, a field replaceable unit may contain other field replaceable units. Contrast with customer-replaceable unit (CRU).

File Image Capture (FIC). Function that takes a file system clone and a read-only copy of the certain read-write (active) file system. File Image Capture reflects the state of the file system at the time it was created.

File Image Restore. Function that allows a file system to revert to the state and contents of a previous File Image Capture. This function can be used to recover a corrupted file system.

File Transfer Protocol (FTP). In the Internet suite of protocols, an application layer protocol that uses TCP and Telnet services to transfer bulk-data files between machines or hosts.

FIR (see File Image Restore).

firewall. A logical barrier around systems in a network. A firewall consists of hardware, software, and a security policy that control the access and flow of information between secure or trusted systems and nonsecure or untrusted systems.

fixed-length record. A record having the same length as all other records with which it is logically or physically associated.

flash memory. A memory chip that holds its content without power but must be erased in fixed blocks rather than single bytes.

floating virtual connection (FVC). The ability to resume a virtual connection on a port other than the port connection on which the original virtual connection was established.

frame alignment error. An error in a frame, indicated by a frame check sequence (FCS) indicator. When excessive or missing bits occur during the reception of a frame, the frame is misaligned.

free disk. A physical disk that is not assigned as a hot-spare, as a standby hot-spare, or to a logical drive.

FRU (see field-replaceable unit).

FTP (see File Transfer Protocol).

FVC (see floating virtual connection).

G

gateway. A device that acts as a router, but occurs at the transport layer, to transfer packets between networks.

group definition. A list of directory numbers.

group definition ID. The identifier of a group definition.

group SAP. A single address assigned to a group of service access points (SAPs).

group separator (GS) character. The information separator intended to identify a logical boundary between groups.

H

hard failure. An error condition on a network that requires that the network be reconfigured or that the source of the error be removed before the network can resume reliable operation. Synonym for hard error.

hertz (Hz). A unit of frequency equal to one cycle per second.

Note: In the United States, line frequency is 60 Hz or a change in voltage polarity 120 times per second; in Europe, line frequency is 50 Hz or a change in voltage polarity 100 times per second.

114NAS 200 User’s Reference