HP-UX Reference (11i v1 05/09) - 7 Device (Special) Files, 9 General Information, Index (vol 10)
m
mt(7) mt(7)
DLT Selects one of the known DLT formats; can be used to specify DLT42500_24,
DLT42500_56, DLT62500_64, DLT81633_64,orDLT85937_52,asrequired.
QIC Selects one of the known QIC formats; can be used to specify QIC11, QIC24,
QIC120, QIC150, QIC525, QIC1000, QIC1350, QIC2100, QIC2GB,orQIC5GB,
as required.
D8MM Selects one of the known 8MM formats; can be used to specify D8MM8200 or
D8MM8500,asrequired.
D Selects a reel-to-reel density; can be used to specify D800, D1600,orD6250,as
required.
D3480 Specifies that the device special file communicates with a 3480 device. (There is
only one density option for 3480.)
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.)
Sample Tape Device Special File Names
For a QIC150 device at SCSI address 3, card instance 2, with default block size, buffered mode, and AT&T-
style with rewind on close, the standard device special file name is /dev/rmt/c2t3d0QIC150
.
For a device at card instance 1, target 2, LUN 3, with exhaustive mode enabled (see DEPENDENCIES),
fixed block size of 512 bytes, DDS1 density with compression, AT&T-style with no rewind on close, the stan-
dard device file special name is
/dev/rmt/c1t2d3es512DDS1Cn
.
For a system requiring short file names, the same device special file would be named
/dev/rmt/c1t2d3i<#>n
, where <#> is an index value selected by the tape driver.
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. For QIC devices only one
EOF mark is written and the tape is positioned after the EOF mark (if the no-rewind mode has been
specified).
When a file open for reading (only) is closed and the no-rewind bit is not set, the tape is rewound. If the
no-rewind bit is set, the behavior depends on the style mode. For AT&T-style devices, the tape is positioned
after the EOF following the data just read (unless already at BOT or Filemark). For Berkeley-style devices,
the tape is not repositioned in any way.
Each read(2) or write(2) call reads or writes the next record on the tape. For writes, the record has the
same length as the buffer given (within the limits of the hardware).
Section 7−−76 Hewlett-Packard Company − 2 − HP-UX 11i Version 1: September 2005