Technical data

st(7D) Devices SunOS 5.5

NAME st − driver for SCSI tape devices

SYNOPSIS st@target,lun:[l,m,h,c,u][b][n]

DESCRIPTION The st device driver is an interface to various SCSI tape devices. Supported tape devices

include 1/4” Tandberg 2.5 Gigabyte QIC tape drive, 1/4” Archive Viper QIC-150 stream-

ing tape drive, 1/4” Emulex MT-02 tape controller, HP-88780 1/2” tape drive, Exabyte

EXB-8200/8500/8505/8505XL 8mm cartridge tape, and the Archive Python 4 mm DAT

tape subsystem. st provides a standard interface to these various devices; see mtio(7I) for

details.

The driver can be opened with either rewind on close or no rewind on close options. A

maximum of four tape formats per device are supported (see FILES below). The tape

format is speciﬁed using the device name. Often tape format is also referred to as tape

density.

Read Operation If the driver is opened for reading in a different format than the tape is written in, the

driver overrides the user selected format. For example, if a 1/4” cartridge tape is written

in QIC-24 format and opened for reading in QIC-150, the driver will detect a read failure

on the ﬁrst read and automatically switch to QIC-24 to read the data.

Note that if the low density format is used, no indication is given that the driver has over-

ridden the user selected format. Other formats issue a warning message to inform the

user of an overridden format selection. Some devices automatically perform this func-

tion and do not require driver support (1/2” reel tape drive, for example).

Write Operation Writing from the beginning of tape is performed in the user-speciﬁed format. The origi-

nal tape format is used for appending onto previously written tapes.

Tape Conﬁguration The st tape driver has a built-in conﬁguration table for all Sun supported tape drives. In

order to support the addition of third party tape devices or to override a built-in

conﬁguration, drive information can be supplied in st.conf as global properties that

apply to each node, or as properties that are applicable to one node only. The st driver

looks for the property called “tape-conﬁg-list”. The value of this property is a list of tri-

plets, where each triplet consists of three strings.

The formal syntax is:

tape-conﬁg-list = <triplet>[, <triplet> ∗];

where

and

<data-property-name> = <version>, <type>, <bsize>,

<options>, <number of densities>,

<density> [, <density>∗], <default-density>;

7D-304 modiﬁed 30 Aug 1995