SCF Reference Manual for the Storage Subsystem (G06.27+, H06.04+)

Configuring and Managing Tape Drives
SCF Reference Manual for the Storage Subsystem—529937-008
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Displaying Status Information
Buffer Level the level of buffering provided by the tape process. Buffering can
increase the performance of a write operation when no errors occur.
Values can be:
UNSUPPORTED—The buffering level is unsupported or unknown.
RECORD—No buffering is performed on tape writes (every record
written to the tape process is passed to the tape drive immediately).
FILE—File buffering is performed on tape writes (records are passed
to the tape drive only when a file mark is written). Therefore, an
application might have to rewrite all records written since the last file
mark if an unrecoverable error occurs during a write to tape.
REEL—Reel buffering is performed on tape writes (even file marks
are buffered). Therefore, that an application might have to rewrite
the whole reel if an unrecoverable error occurs during a write.
Checksum
Mode
shows the current checksum method in use. Values can be:
CHECKSUM—Checksum processing is performed when a record is
read (the checksum of the record is appended to the record after it is
read). The tape process computes the checksum of the record and
appends the checksum to the end of the record. On a successful
read, an FESUMREADOK message is returned (instead of an
FEOK).
NORMAL I/O—No special checksum processing is performed.
Compression for cartridge tape drives, shows whether compression is configured.
This setting is ignored by 5194 tape drives because compression is
always on. For other tape drives, this field is not applicable (N/A).
Density the configured tape density in bits per inch (bpi) of a 5170 tape drive.
Media Type the type of media in the tape drive. The type of media can be
UNKNOWN, 9-TRACK, 18-TRACK, or 36-TRACK.
Opens the maximum concurrent opens to the tape process.
RecSize the configured record size for the tape drive (in bytes).