NAME

st − streaming-tape interface

SYNOPSIS

controller stc0 at iocc0 csr 0xf00001e8 priority 12
tape st0 at stc0 drive 0

DESCRIPTION

The streaming-tape driver provides a QIC 02 (Quarter-Inch Cartridge) tape interface.  The device is used to back up data on hard disks.  The adapter uses programmed I/O for the 16-bit data transfers to and from its 512-byte sector buffer.  When writing to the tape, the block interface generally gives better performance than the raw interface for transfers smaller than 100 sectors.  Note, however, that errors detected when writing to the block interface might not be returned to the program; errors detected when writing to the raw interface are returned.

Writes to the block tape device must be multiples of 2k in length. 

When reading the tape, the raw interface gives better performance. 

For example, to dump a filesystem g, type:

dump 0f /dev/rst0 /dev/rhd0g

To restore the filesystem to the current directory, type:

mount /dev/hd0g /mnt
cd /mnt
restore rvf /dev/rst0

Erase brand-new tapes before use, with the command:

mt -f /dev/rst0 erase

FILES

/dev/nst0
/dev/nrst0

SEE ALSO

mt(1), tar(1), mtio(4), dump(8), restore(8)

DIAGNOSTICS

st%d: write protected.  An attempt was made to write on the tape drive while the tape was write-protected. 

st%d: hard error bn%d er=%b.   A tape error occurred at block bn.  Any error is fatal on non-raw tape; when possible, the driver will retry the failed operation several times before reporting the error. 

st%d: lost interrupt.  A tape operation did not complete within a reasonable time.  This can occur if you open the tape door before the tape drive has been closed or stops moving. 

BUGS

The streaming tape hardware backspace operation is exceedingly slow.  For this reason the backspace-file command has not been implemented. 

PRPQs 5799-WZQ/5799-PFF: IBM/4.3  —  July 1987