tz(7) — Special Files
Digital
NAME
tz − SCSI magnetic tape interface
SYNOPSIS
RISC DEC SII:
adapter ibus0 at nexus?
controller sii0 at ibus? vector sii_intr
tape tz0 at sii0 drive 0 RISC DEC KZQ:
adapter uba0 at nexus?
controller kzq1 at ibus? csr 0761300 vector kzq_intr
tape tz0 at kzq1 drive 0 RISC NCR ASC:
adapter ibus0 at nexus?
controller asc0 at ibus? vector ascintr
tape tz0 at asc0 drive 0
DESCRIPTION
The SCSI tape driver provides a standard tape drive interface as described in mtio(7). This is the tape driver for any Digital SCSI tape device. Facilities are provided to allow addition of third party SCSI tape drives to the system. Refer to the /usr/sys/data/cam_data.c file for instructions.
For reads from Beginning of Media (BOM), the density and blocking factors of the tape are obtained from the drive. Auto density selection is then used for all read operations. This means that reads are performed in the density and blocking factor of the tape. For writes from BOM, the density and blocking factor of the tape are overidden. The tape is written in the density and blocking factor that the user has selected by specifying one of the following device special files: rmt?a; rmt?l; rmt?m; or rmt?h.
The following are default densities for specific SCSI tape drives:
TZ30: Single-density drive.
rmt?a 6666 BPI
rmt?l 6666 BPI
rmt?m 6666 BPI
rmt?h 6666 BPI
TZ50: Single-density drive.
rmt?a 6666 BPI
rmt?l 6666 BPI
rmt?m 6666 BPI
rmt?h 6666 BPI
TZ85: Write, single-density-drive.
Read, TZ50, TZ30 and TZ85 formats.
rmt?a 42500 BPI
rmt?l 42500 BPI
rmt?m 42500 BPI
rmt?h 42500 BPI
TLZ04: Single-density drive.
rmt?a 61000 BPI
rmt?l 61000 BPI
rmt?m 61000 BPI
rmt?h 61000 BPI
TLZ06: Single-density drive, compaction support.
rmt?a 61000 BPI
rmt?l 61000 BPI
rmt?m 61000 BPI, compaction turned on.
rmt?h 61000 BPI, compaction turned on.
TSZ07: Triple-density drive.
rmt?a 6250 BPI
rmt?l 800 BPI
rmt?m 1600 BPI
rmt?h 6250 BPI
TKZ08: Single-density drive.
rmt?a 54000 BPI
rmt?l 54000 BPI
rmt?m 54000 BPI
rmt?h 54000 BPI
TKZ09: Dual-format drive, supports Exabyte 8200 and 8500
formats
rmt?a 54000 BPI (8200 format)
rmt?l 54000 BPI (8200 format)
rmt?m 54000 BPI (8500 format)
rmt?h 54000 BPI (8500 format)
TZK10: Quad-format drive.
See description below.
The following formats are supported for the TZK10 QIC-format tape drive: QIC-24 (read only) 512-byte block size; QIC-120 and QIC-150 (read/write) 512-byte block size; and QIC-320 (read/write) 512-byte block size. With QIC-format tapes, all read and write operations must be in multiples of the block size because record boundaries are not preserved. Use the following device special file names to select QIC densities:
rmt?aQIC-24 Fixed block size.
rmt?lQIC-120 Fixed block size.
rmt?mQIC-150 Fixed block size.
rmt?hQIC-320 Fixed block size.
With all fixed-block tape devices, when you us the dd command to transfer a file to tape you must use padding to complete a block by specifying the conv=sync option. For example, the following commands use the dd command with the conv=sync option to transfer an /etc/motd file with a size of approximately 400 bytes over two QIC-format tape drives:
dd if=/etc/motd of=/dev/rmt0h bs=10k conv=sync
dd if=/etc/motd of=/dev/rmt0l bs=512 conv=sync
Tape Support
The following tape drives are supported: TZ30; TZK50; TZ85; TLZ04; TLZ06; TSZ07; TKZ08; TKZ09; and TZK10.
ERRORS
All diagnostic messages are sent to the error logger subsystem.
FILES
/dev/rmt???, /dev/nrmt???