smt - magnetic tape control
smt [ -f tapename ] command [
count ]
The smt program sends commands to a local or a remote
magnetic tape drive.
The count operand specifies the number of times the
requested command is to be performed. If count is omitted, the value
of count defaults to one.
- -help
- Prints a summary of the options for smt(1) and exits.
- -version
- Prints the smt version number string and exists.
- -debug
- print additional debug messages.
- -f tapename
- -t tapename
- Set the raw tape device to use, otherwise smt uses a system
specific default for the rtape device. If smt is installed suid
root or if it has been called by root, tapename may be in remote
syntax: user@host:filename as in rcp(1) even if invoked by non root
users. See SUID NOTES for more information.
To make a file local although it includes a colon (:), the
filename must start with: '/', './' or '../'
Note that if smt talks to an old rmt remote tape
server that does not support symbolic open modes, it does not open a
remote tape with the O_CREAT open flag because this would be
extremely dangerous. If the rmt server on the other side is the
rmt server that comes with star or the GNU rmt
server, smt may use the symbolic mode for the open flags. Only
the symbolic open modes allow sending all possible open modes in a
portable way to remote tape servers.
It is recommended to use the rmt server that comes with
star. It is the only rmt server that gives platform
independent compatibility with BSD, Sun and GNU rmt clients and
it includes security features that may be set up in
/etc/default/rmt.
See ENVIRONMENT section for information on how to use
ssh(1) to create a remote tape server connection.
- -wready
- Wait for the tape drive to become ready before executing the command.
The following commands are supported:
- eof
- weof
- Write count EOF (FILE) marks at the current position on the tape.
This command may be run remotely with any BSD compliant old
rmt server.
- fsf
- Forward skip over count FILE marks. The tape is positioned on the
first block of the file.
This command may be run remotely with any BSD compliant old
rmt server.
- bsf
- Backward skip count FILE marks. The tape is positioned on side of
the FILE mark that is closer to the beginning of the tape.
This command may be run remotely with any BSD compliant old
rmt server.
- asf
- Absolute FILE mark positioning to file number count. This is
equivalent to a rewind followed by a fsf count.
A RMT version 1 server is needed to run this command on a
remote tape drive.
- fsr
- Forward skip count tape records.
This command may be run remotely with any BSD compliant old
rmt server.
- bsr
- Backward skip count tape records.
This command may be run remotely with any BSD compliant old
rmt server.
- rewind
- Rewind the tape.
This command may be run remotely with any BSD compliant old
rmt server.
- offline
- rewoffl
- Rewind the tape. If the specified tape drive allows one to take the drive
off-line or to unload the tape, a off-line or unload operation is
performed in addition.
This command may be run remotely with any BSD compliant old
rmt server.
- status
- Retrieve and print status information for the tape drive.
A RMT version 1 server is needed to get correct status
information on a remote tape drive.
- nop
- No operation. If you only like to wait for the tape drive to become ready,
call smt -wready nop.
This command may be run remotely with any BSD compliant old
rmt server.
- retension
- Retension the tape. This only makes sense with cartridge tape drives.
A RMT version 1 server is needed to run this command on a
remote tape drive.
- erase
- Erase the entire tape. This may take a long time (up to several hours)
depending on the tape drive and the medium.
A RMT version 1 server is needed to run this command on a
remote tape drive.
- eom
- Position the tape to the end of the recorded media. This allows one to
append data to previously written tapes.
A RMT version 1 server is needed to run this command on a
remote tape drive.
- nbsf
- Backward skip count FILE marks. The tape is positioned on side of
the FILE mark that is closer to the end of the tape. This is before the
first block of the file. The nbsf command is equivalent to
count+1 bsf's followed by one fsf.
A RMT version 1 server is needed to run this command on a
remote tape drive.
- load
- If the specified tape drive allows one to take the drive on-line or to
load the tape, a on-line or load operation is performed. in addition. For
remote tape drives, this command only works if the remote tape server
supports symbolic open modes as the command needs the O_NDELAY flag
to succeed.
A RMT version 1 server is needed to run this command on a
remote tape drive.
- RSH
- If the RSH environment is present, the remote connection will not
be created via rcmd(3) but by calling the program pointed to by
RSH. Use e.g. RSH=/usr/bin/ssh to create a secure shell
connection.
Note that this forces smt to create a pipe to the
rsh(1) program and disallows smt to directly access the
network socket to the remote server. This makes it impossible to set up
performance parameters and slows down the connection compared to a
root initiated rcmd(3) connection.
- RMT
- If the RMT environment is present, the remote tape server will not
be the program /etc/rmt but the program pointed to by RMT.
Note that the remote tape server program name will be ignored if you log
in using an account that has been created with a remote tape server
program as login shell.
- TAPE
- In case no -f option pas been specified, the default tape name is
taken from the TAPE environment.
spax(1), suntar(1), scpio(1), tar(1),
cpio(1), pax(1), rcp(1), mt(1), rmt(1),
match(1), dd(1), sdd(1), rsh(1), ssh(1),
star(1), star(4/5), rcmd(3),
If the remote tape server is running Linux and the remote tape
server on such a system is not the rmt server that comes with
star(1), then completely unexpected results (including unexpectedly
erased tapes) may occur. This is because Linux ignores the numbering values
for the magnetic tape op codes and only the rmt server from star(1)
maps to standard values. The standard rmt server on Linux for this reason
may not be called BSD compliant.
None currently known.
Mail bugs and suggestions to
schilytools@mlists.in-berlin.de or open a ticket at
https://codeberg.org/schilytools/schilytools/issues.
The mailing list archive may be found at:
https://mlists.in-berlin.de/mailman/listinfo/schilytools-mlists.in-berlin.de.
Joerg Schilling and the schilytools project authors.
The source code for smt is included in the
schilytools project and may be retrieved from the schilytools
project at Codeberg at
https://codeberg.org/schilytools/schilytools.
The download directory is
https://codeberg.org/schilytools/schilytools/releases.