Glossary188
ECMA European Computer Manufacturers Association. The European equivalent of
ANSI.
enhanced commandsSCSI commands that are vendor-unique and not part of the common SCSI set.
EOD End Of Data. An area that signifies the end of the valid data. If new data is
written over a larger quantity of old data, it is possible for data to exist after EOD,
but because it is after EOD, this old data is no longer valid.
EOM End Of Media format. The last usable point on the tape.
EW-EOM Early Warning End Of Media. A physical mark or a device-computed position on
the tape that tells the drive that it is approaching EOM.
filemark A mark written by the host. It does not necessarily separate files; it is up to the host
to assign a meaning to the mark.
filemark count The number of filemarks written since the beginning of the current tape up to and
including the current group.
FRU Field Replaceable Unit, an assembly or group of components that is replaced in its
entirety by Service Engineers when it contains a fault.
host The host computer system acting as controller for the drive.
immediate mode A mode of responding to SCSI commands where the drive or other peripheral
does not wait until the command has finished before returning status information
back to the host. For writing filemarks, Immediate mode can significantly improve
the performance of systems that do not set the Immediate bit when sending a SCSI
Write Filemarks command. On the other hand, data is not flushed to tape in
response to a filemark command.
load The process in which the drive takes in an inserted cartridge and goes online.
LUN Logical Unit Number, by which different devices at a particular SCSI ID can be
addressed individually. The drive has a fixed LUN of 0.
LVD Low-Voltage Differential. See SCSI.
RAW see read-after-write
read-after-write RAW improves data integrity by reading data immediately after it is written and
writing the data again if an error is found.
reserved Not generally available for use with the drive. A reserved field should contain all
zero bits.
