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(ADM)
or
read(S),
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(ADM))
without using the read-only flag, -r.
ioctl calls
The
ioctl(S)
calls supported by the sw01 driver are documented
on the
sdi(HW)
manual page.
Files
The following worm special files are provided for SCO Open Server Release 6.0.0.
In the following table, 'C' is the controller number of the Host Adapter that
the worm drive is attached to, 'B' is the bus or channel number that the worm drive
is attached to and 'T' is the target ID of the worm drive.
Also, 'U' is the worm drive's number in the system, starting at 0 ( zero ).
For example, the first worm drive in the system could be referenced as /dev/rworm/worm0