NAME
smt - magnetic tape control
SYNOPSIS
smt [ -f tapename ] command [ count ]
DESCRIPTION
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.
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.
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.
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.
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 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 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.
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 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.
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.
BUGS
AUTHOR
Joerg Schilling
Seestr. 110
D-13353 Berlin
Germany
Mail bugs and suggestions to:
schilling@fokus.fraunhofer.de or js@cs.tu-berlin.de or
joerg@schily.isdn.cs.tu-berlin.de