SCUZZ(8) SCUZZ(8)
NAME
scuzz - SCSI target control
SYNOPSIS
scuzz [ -q ] [ [ -r ] sddev ]
DESCRIPTION
Scuzz is an interactive program for exercising raw SCSI
devices. Its intended purpose is to investigate and manipu-
late odd devices without the effort of writing a special
driver, such as shuffling the media around on an optical
jukebox. It reads commands from standard input and applies
them to a SCSI target (other devices accessed through the
sd(3) interface, such as ATA(PI) devices, may also work).
If sddev is given on the command line, an open (see below)
is immediately applied to the target. On successful comple-
tion of a command, ok n is printed, where n is the number of
bytes transferred to/from the target; the -q command line
option suppresses the ok message.
Commands
help command
Help is rudimentary and prints a one line synopsis for
the named command, or for all commands if no argument
is given.
probe
Probe attempts an inquiry command on all SCSI units,
and prints the result preceded by the name of those
targets which respond.
The help and probe commands may be given at any time.
open [-r]sddev
Open must be given before any of the remaining commands
will be accepted. Internally, unless the -r option is
given, open issues ready then inquiry, followed by a
device class-specific command to determine the logical
block size of the target. Sddev is an sd(3) device
directory like /dev/sdC0.
close
Close need only be given if another target is to be
opened in the current session.
The remaining commands are in rough groups, intended for
specific classes of device. With the exception of the read,
write, and space commands, all arguments are in the style of
ANSI-C integer constants.
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ready
Test Unit Ready checks if the unit is powered up and
ready to do read and write commands.
rezero
Rezero Unit requests that a disk be brought to a known
state, usually by seeking to track zero.
rewind
Rewind positions a tape at the beginning of current
partition (there is usually only one partition, the
beginning of tape).
reqsense
Request Sense retrieves Sense Data concerning an error
or other condition and is usually issued following the
completion of a command that had check-condition sta-
tus. Scuzz automatically issues a reqsense in response
to a check-condition status and prints the result.
format
Format Unit performs a ``low level'' format of a disk.
rblimits
Read Block Limits reports the possible block lengths
for the logical unit. Tapes only.
read file nbytes
Read transfers data from the target to the host. A
missing nbytes causes the entire device to be read.
write file nbytes
Write transfers data from the host to the target. A
missing nbytes causes the entire input file to be
transferred.
The first argument to the read and write commands spec-
ifies a source (write) or destination (read) for the
I/O. The argument is either a plain file name or |
followed by a command to be executed by rc(1). The
argument may be quoted in the style of rc(1).
seek offset whence
Seek requests the target to seek to a position on a
disk, arguments being in the style of seek(2); whence
is 0 by default.
Scuzz maintains an internal notion of where the current
target is positioned. The seek, read, write, rewind,
rezero, and wtrack commands all manipulate the internal
offset.
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filemark howmany
Write Filemarks writes one (default) or more filemarks
on a tape.
space [-b] [-f] [[--]howmany]
Space positions a tape forwards or backwards. The
arguments specify logical block (-b) or filemark (-f)
spacing; default is -b. If howmany is negative it
specifies spacing backwards, and should be preceded by
-- to turn off any further option processing. Default
is 1.
inquiry
Inquiry is issued to determine the device type of a
particular target, and to determine some basic informa-
tion about the implemented options and the product
name.
modeselectbytes...
modeselect6bytes...
Mode Select is issued to set variable parameters in the
target. Bytes given as arguments comprise all the data
for the target; see an appropriate manual for the for-
mat. The default is the 10-byte form of the command;
modeselect6 is the 6-byte version.
modesense [page[nbytes]]
modesense6 [page[nbytes]]
Mode Sense reports variable and fixed parameters from
the target. If no page is given, all pages are
returned. Nbytes specifies how many bytes should be
returned. The default is the 10-byte form of the com-
mand; modesense6 is the 6-byte version.
start [code]
stop [code]
eject [code]
ingest [code]
Start, stop, eject, and ingest are synonyms for
Start/Stop Unit with different default values of code.
Start/Stop Unit is typically used to spin up and spin
down a rotating disk drive. Code is 0 to stop, 1 to
start and 3 to eject (if the device supports ejection
of the medium).
capacity
Read Capacity reports the number of blocks and the
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block size of a disk.
The following commands are specific to CD and CD-R/RW
devices. A brief description of each is given; see the
SCSI-3 Multimedia Commands (MMC) Specification for details
of arguments and interpretation of the results.
blank [track/LBA[type]]
Erase a CD-RW disk. Type identifies the method and
coverage of the blanking.
rtoc [track/session-number[ses]]
The Read TOC/PMA command transfers data from one of the
tables of contents (TOC or PMA) on the CD medium.
rdiscinfo
(Note the spelling.) Provides information about disks,
including incomplete CD-R/RW.
rtrackinfo [track]
Provides information about a track, regardless of its
status.
cdpause
cdresume
Pause/resume playback.
cdstop
Stop playback.
cdplay [track-number] or [-r[LBA[length]]]
Play audio. With no arguments, starts at the beginning
of the medium. If a track number is given, the table
of contents is read to find the playback start point.
If the -r option is given, block addressing is used to
find the playback start point.
cdload [slot]
cdunload [slot]
Load/unload a disk from a changer.
cdstatus
Read the mechanism status.
The following commands are specific to Media Changer
devices. A brief description of each is given; see the
SCSI-3 Medium Changer Commands (SMC) Specification for
details of arguments.
einit
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Initialize element status.
estatustype[length]
Report the status of the internal elements. Type 0
reports all element types.
mmovetransport source destination[invert]
Move medium.
FILES
/dev/sdXX/raw raw SCSI interface for command, I/O, and sta-
tus.
SOURCE
/sys/src/cmd/scuzz
SEE ALSO
sd(3)
Small Computer System Interface - 2 (X3T9.2/86-109), .}f
Global Engineering Documents
SCSI Bench Reference, ENDL Publications
SCSI-3 Multimedia Commands (MMC) Specification, www.t10.org
SCSI-3 Medium Changer Commands (SMC) Specification, .}f
www.t10.org
BUGS
Only a limited subset of SCSI commands has been implemented
(as needed).
Only one target can be open at a time.
LUNs other than 0 are not supported.
No way to force 6- or 10- byte commands.
Should be recoded to use scsi(2) in order to get more com-
plete sense code descriptions.
Scuzz betrays its origins by spelling rdiscinfo with a c
even though the devices it manipulates are spelled with a k.
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