Name

tz − SCSI magnetic tape interface

Syntax

VAX NCR 5380:
adapteruba0at nexus? 
controllerscsi0at uba0csr 0x200c0080  vector szintr
tapetz0at scsi0drive 0

VAX DEC SII:
adapteribus0at nexus? 
controllersii0at ibus?vector sii_intr
tapetz0at sii0drive 0

RISC DEC SII:
adapteribus0at nexus? 
controllersii0at ibus?vector sii_intr
tapetz0at sii0drive 0

RISC DEC KZQ:
adapteruba0at nexus? 
controllerkzq1at uba0csr 0761300 vector kzq_intr
tapetz8at kzq1drive 0
controllerkzq2at uba0csr 0761400 vector kzq_intr
tapetz16at kzq2drive0

RISC NCR ASC:
adapteribus0at nexus? 
controllerasc0at ibus?vector ascintr
tapetz0at asc0drive 0

Description

The SCSI tape driver provides a standard tape drive interface as described in mtio(.). This is a driver for any Digital SCSI tape device.

For the TZK10 QIC format tape drive, the densities supported are QIC-24 (read only) block size of 512 byte blocks, QIC-120, and QIC-150 read/write block size of 512 byte blocks, and QIC-320 read/write block size of 1024 byte blocks.  With QIC format style tapes all reads and writes must be in multiple of the block size.  This is a requirement of fixed block tape drives because record boundaries are not preserved.  The QIC densities are selected using the following special device names:

rmt?a QIC-24 Fixed block size. 
rmt?l QIC-120 Fixed block size. 
rmt?m QIC-150 Fixed block size. 
rmt?h QIC-320 Fixed block size. 

With all fixed block tape devices a dd of a file to the tape must be padded out.  An example of this is a dd of /etc/gettytab which has a size of approximately 3800 bytes.

dd if=/etc/gettytab of=/dev/rmt0h bs=10k conv=sync
or
dd if=/etc/gettytab of=/dev/rmt0l bs=512 conv=sync

The option of conv=sync pads the output to block size.

This driver also supports n-buffered reads and writes to the raw tape interface (used with streaming tape drives).  See nbuf() for further details.

Tape Support

Consult the ULTRIX Software Product Description to determine which drives are supported for different CPU types and hardware configurations. 

Diagnostics

All diagnostic messages are sent to the error logger subsystem. 

Files

/dev/rmt???
/dev/nrmt???

See Also

mtio(4), nbuf(4), SCSI(4), MAKEDEV(8), uerf(8), tapex(8)
Guide to the Error Logger