Schily's USER COMMANDS SMT(1)
NAME
smt - magnetic tape control
SYNOPSIS
smt [ -f tapename ] command [ count ]
DESCRIPTION
The smt program sends commands to a local or a remote mag-
netic 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.
OPTIONS
-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 to send 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.
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Schily's USER COMMANDS SMT(1)
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 execut-
ing the command.
COMMANDS
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.
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offline
rewoffl Rewind the tape. If the specified tape drive
allows to take the drive off-line or to unload
the tape, a off-line or unload operation is per-
formed 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 sende 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 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.
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Schily's USER COMMANDS SMT(1)
load If the specified tape drive allows 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.
EXAMPLES
ENVIRONMENT
RSH If the RSH environment is present, the remote connec-
tion 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.
FILES
SEE ALSO
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),
DIAGNOSTICS
NOTES
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.
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Schily's USER COMMANDS SMT(1)
BUGS
AUTHOR
Joerg Schilling
D-13353 Berlin
Germany
Mail bugs and suggestions to:
joerg@schily.net
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