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 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.

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.

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.

Jorg 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