NAME

tz − SCSI magnetic tape interface

SYNOPSIS

DEC 7000 DEC XZA:
  bus lsb0 at nexus? 
 bus iop0 at lsb0 vector ioperror
 bus xmi0 at iop0 vector xmierror
 bus xza0 at xmi?
 controller skz0 at xza0
 controller skz1 at xza0
 tape tz0 at skz0 drive 0
 tape tz8 at skz1 drive 64 DEC 4000 DEC SIOP:
  bus ibus0 at nexus? 
 bus lbus0 at ibus0?
 controller siop0 at lbus0 slot 0 vector siopcointr
 controller siop1 at lbus0 slot 1 vector siopcointr
 tape tz0 at siop0 drive 0
 tape tz9 at siop1 drive 72 DEC 3000 NCR ASC:
  bus tc0 at nexus? 
 bus tcds0 at tc0 vector tcdsintr
 controller asc0 at ∗ vector tcdsintr
 controller asc1 at ∗ vector tcdsintr
 tape tz0 at asc0 drive 0
 tape tz10 at asc1 drive 80 DEC 3000 DEC KZTSA:
 
 controller tzan at ∗ vector kztsa_intr
 controller tzan at ∗ vector kztsa_intr
 disk rznn at tzan drive nnn
 disk rznn at tzan drive nnn
 tape tznn at tzan drive nnn
 tape tznn at tzan drive nnn

DESCRIPTION

The Small Computer System Interface (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 the 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 of the tape is obtained from the drive.  Autodensity selection is then used for all read operations.  This means that reads are performed in the density of the tape.  For writes from BOM, the density and blocking factor of the tape are set.  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 the 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
    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 (Exabyte 8200).
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 45434 BPI (8500 format)
rmt?h 45434 BPI (8500 format)
    TZK10: Quad-format drive.
 See description that follows.
    TZK11: QIC-format drive.
See description that follows.

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) variable block size.  With QIC-format tapes, except QIC-320 and QIC-525, 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:

The following formats are supported for the TZK11 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-320/525/1Gig/2Gig (read/write) variable block size.  With QIC-format 24/120/150 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:

The TZK11 tape drive uses autodensity select feature of the drive. The 2 Gig density can only be written on a 2 Gig cartridge.  The 1 Gig density can only be written on a 1 Gig cartridge.  The 320/525 cartridge can be used to write 120/150/320/525 densities. With all fixed-block tape devices, when you use 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 two dd commands use the conv=sync option to transfer the /etc/motd file with a size of approximately 400 bytes to the QIC-format tape drives:

dd if=/etc/motd of=/dev/rmt0m bs=10k conv=sync

dd if=/etc/motd of=/dev/rmt0l bs=512 conv=sync

Tape Support

Refer to the Software Product Description (SPD) for information on the hardware that is supported on the various system platforms. 

EXAMPLES

The following example shows the configuration specification that you might have for a DEC 3000 Model 500 system with a PMAZB controller in slot 0 and KZTSA devices in slots 1 and 2:

bus tc0 at nexus?
controller tza4 at ∗ vector kztsa_intr
controller tza5 at ∗ vector kztsa_intr
disk rz32 at tza4 drive 256
disk rz40 at tza5 drive 320
tape tz32 at tza4 drive 256
tape tz40 at tza5 drive 320

ERRORS

All diagnostic messages are sent to the error logger subsystem. 

FILES

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

RELATED INFORMATION

mtio(7), RAID(7), SCSI(7), MAKEDEV(8), uerf(8), tapex(8)