ST(4S) — SPECIAL FILES

NAME

st − Driver for Sysgen SC 4000 Tape Controller

SYNOPSIS

controller sc0 at mb0 csr 0x80000 priority 2
controller sc0 at mb0 csr vme busmem 0x200000 priority 2 vector scintr 64
tape st0 at sc0 drive 32 flags 1

DESCRIPTION

In the synopsis lines above, the first line specifies the first SCSI controller on a Sun-2/120 or Sun-2/170; the second specifies the first such controller on a Sun-2/160. The last line specifies the first tape drive on the first SCSI controller in a system.

The Sysgen tape controller is a SCSI bus interface to a streaming tape drive. It provides a standard tape interface to the device, see mtio(4), with some deficiencies listed under BUGS below. To utilize the QIC 24 format, access the logical device that is eight above the default physical (QIC 11) device (i.e. rst0 = QIC 11, rst8 = QIC 24).

FILES

/dev/rst[0-3]QIC 11 Format
/dev/rst[8-11]QIC 24 Format
/dev/nrst[0-3]non-rewinding

DIAGNOSTICS

st∗: tape not online.

st∗: no cartridge in drive.

st∗: cartridge is write protected.

st∗: format change failed.

st∗: device not supported.

BUGS

The tape cannot reverse direction so the BSF and BSR ioctls are not supported.

The FSR ioctl is not supported.

Most disk I/O over the SCSI bus is prevented when the tape is in use. This is because the controller does not free the bus while the tape is in motion (even during rewind).

When using the raw device, the number of bytes in any given transfer must be a multiple of 512. If it is not, the device driver returns an error.

The driver will only write an end of file mark on close if the last operation was a write, without regard for the mode used when opening the file. This will cause empty files to be deleted on a raw tape copy operation.

Some older systems may not support the QIC 24 device, and may complain (or exhibit erratic behavior) when the user attempts a QIC 24 device access.

Sun Release 2.2 — Last change: 04 February 1985

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