sw01(7)

sw01 -- Storage Device Interface (SDI) WORM Target Driver

Description

The sw01 driver is an SDI-compliant Write Once Read Many (WORM) target driver that provides access to one or more WORM drives. Each drive must be attached to a SCSI Bus that is controlled by an SDI-compliant host adapter driver.

Access to the particular drive is accomplished through the sw01 device nodes located in /dev/[r]worm.

Each device node identifies a particular drive based on the SCSI ID assigned to that drive. The binding between a device node and a WORM drive is as follows:

/dev/rworm/worm0: WORM drive with lowest SCSI ID
/dev/rworm/worm1: WORM drive with next to lowest SCSI ID

and so on.

A WORM drive uses removable media divided into consecutively numbered, fixed-size sectors that can be accessed in any order, similar to a hard disk. Most of the standard tools for reading and writing to and from a hard disk, such as dd(1M) or read(2), work with a WORM drive. However, keep in mind that for WORM drives, each sector can be written to only once. This characteristic causes problems if a WORM device is mounted (mount(1M)) without using the read-only flag, -r.

sw01 device nodes

/dev/worm

Nodes in this directory provide ``Block I/O'' access to the represented WORM drives:

cCbBtTlL

C: Controller Number
B: SCSI Bus Number
T: SCSI Target ID
L: SCSI Logical Unit Number

/dev/rworm

Nodes in this directory provide Raw (Character) I/O access to the represented WORM drives.

cCbBtTlL

C: Controller Number
B: SCSI Bus Number
T: SCSI Target ID
L: SCSI Logical Unit Number

wormN

N: The drive number. The drives are numbered sequentially starting at 1 as they are found by the system.

ioctl calls

The ioctl(2) calls supported by the sw01 driver are documented on the sdi(7) manual page.

Files

/usr/include/sys/sw01.h
/etc/conf/pack.d/sw01/space.c
/dev/[r]worm/*
/usr/include/sys/scsi.h
/usr/include/sys/sdi.h
/usr/include/sys/sdi_edt.h

References

adsc(7), dpt(7), ioctl(2), mcis(7), mount(1M), sc01(7), sd01(7), sdi(7), st01(7), wd7000(7)