mt.7 (2010 09)

m
mt(7) mt(7)
data and return immediately with successful status.
density Density or format used in writing data to tape. This field is designated by the following values:
BEST Highest-capacity density or format will be used, including data compression, if
the device supports compression.
NOMOD Maintains the density used for data previously written to the tape. Behavior
using this option is dependent on the type of device. This option is only supported
on DDS drives.
DDS Selects one of the known DDS formats; can be used to specify
DDS1 or DDS2,as
required.
DLT Selects one of the known DLT formats; can be used to specify
DLT42500_24,
DLT42500_56, DLT62500_64, DLT81633_64,orDLT85937_52
,as
required.
D[#] Specifies density as a numeric value to be placed in the SCSI mode select block
descriptor. The header file
<sys/mtio.h> contains a list of the standard den-
sity codes. The numeric value is used only for density codes which cannot be
found in this list.
C[#] Write data in compressed mode, on tape drives that support data compression. If a number is
included, use it to specify a compression algorithm specific to the device. Note, compression is
also provided when the density field is set to BEST.
n No rewind on close. Unless this mode is requested, the tape is automatically rewound upon
close.
b Specifies Berkeley-style tape behavior. When the
b is absent, the tape drive follows AT&T-
style behavior. The details are described in Tape Behavioral Characteristics below.
f# Specify format (or density) value encoded in the minor number. The meaning of the value is
dependent on the type of tape device in use. (Used for short file name notation only.)
i# Specify an internal Property Table index value maintained by the tape driver, containing an
array of configuration options. The contents of this table are not directly accessible. Use the
lssf (1M) command to determine which configuration options are invoked. (Used for short file
name notation only.)
o Console message disabled. See mksf(1M).
z RTE compatible close. See mksf(1M).
e Exhaustive mode. See DEPENDENCIES section.
p Tape partition. See DEPENDENCIES section.
s Fixed-block mode. See DEPENDENCIES section.
#
m For pre-HP-UX 10.x device file naming convention.
Sample Tape Device Special File Names
For a HP Ultrium-2 drive at card instance 1, target 2, LUN 3 the legacy DSFs would be
/dev/rmt/c1t2d3BEST[n][b]. The corresponding persistent DSFs assuming an instance number "1"
allocated to the DSF would be /dev/rtape/tape1_BEST[n][b]. Corresponding device special files in
the pre-HP-UX 10.0 naming convention would be
/dev/rmt/0m[n][b]. In this particular example, 0
(zero) in 0m[n][b] denotes an instance number of 0 (zero) assigned to the DSF. The files in the
/dev/rmt/#m[n][b] format are created as hardlinks to the corresponding
/dev/rmt/c#t#d#BEST[n][b]DSFs.
Use the lssf(1M) command to determine which configuration options are actually used with any device
file. The naming convention defined above should indicate the options used, but device files may be
created with any user defined name.
Tape Behavioral Characteristics
When opened for reading or writing, the tape is assumed to be positioned as desired.
When a file opened for writing is closed, two consecutive EOF (End of File) marks are written if, and only
if, one or more writes to the file have occurred. The tape is rewound unless the no-rewind mode has been
specified, in which case the tape is positioned before the second EOF just written.
2 Hewlett-Packard Company − 2 − HP-UX 11i Version 3: September 2010