scu - SCSI CAM Utility Program
/sbin/scu [-options ...] [command [keywords...]]
Specifies the user agent path. Use an exclusive open. If
you do not specify this option, a device is closed after
the scu utility obtains its SCSI address information.
Specify the raw device path name. You must specify a character
device special file, for example, /dev/rdisk/dsk10c.
If the device name is not specified on the command
line, the program checks the environment variable
SCU_DEVICE to define the device name. Do not execute
a startup script. Disable device directory
scanning. This is the default mode unless you
specify the -S option. Enable pipe operation mode.
Specify a script startup file name. Enable device
directory scanning.
The SCSI utility program, scu, interfaces with the CAM I/O
subsystem and the peripherals attached to the SCSI buses.
Use this program to maintain and diagnose problems with
SCSI peripherals and the CAM I/O subsystem.
Warning
Data corruption can occur when the write back cache is
enabled using the scu utility. Do not enable the write
back cache.
If you enter the scu command without options it enters
interactive mode. The scu> prompt is displayed until you
terminate the utility by using the exit option. You can
abbreviate options to the least unambiguous number of
characters. The following rules determine how the scu
utility initializes: If you do not specify a device name
on the command line, the scu utility defaults to the environment
variable SCU_DEVICE, providing that variable is
defined. If you do not specify a startup_file by using
the -s option, the scu utility checks the SCU_SCRIPT environment
variable and if defined, uses the value of that
variable. If neither of the preceding conditions are
true, the scu utility checks for a initialization file,
first in the current directory and then in the user's
$HOME path.
The device directory scanning option is disabled by
default on Tru64 UNIX systems. You can set the environment
variable SCU_DEVICE_SCANNING {yes|no} to enable
directory scanning. Directory scanning only occurs during
a scu show edt"command.
The scu utility program has an extensive help feature.
Log in as root and enter /sbin/scu help at the command
prompt to view the help overview and enter a ? at the
topic> prompt to view a list of the utility's commands and
conventions.
The file /sbin/scu.hlp contains the help information used
in the help feature.
Some common device maintenance tasks that you can perform
by using the scu utility are: Formatting disks, diskettes
and optical media Scanning media for bad blocks and reassigning
bad blocks Verifying media (non-destructively)
Viewing device defect lists Downloading new firmware Moving
media in jukeboxes. Obtaining device information,
such as product and vendor names, firmware revision,
serial numbers, device capacity, block size, media type,
and tape density
Some common diagnostic and test functions that you can
perform by using the scu utility are: Execute device diagnostics,
such as self-tests modify mode parameters Display
log pages (such as error counters) Test read/write media
testing Test read/write controller memory Tape erase or
re-tensioning Generate hard or soft media errors Obtain
performance information CD-ROM audio operations Diagnose
hardware problems
The following table summarizes the scu commands and their
functions. Refer to the help command for complete syntax
and examples of use.
------------------------------------------------------------------
Command Function
------------------------------------------------------------------
allow Allows media removal from a device
change Changes mode pages for a device
download Downloads microcode to a device
dump Dumps data from a device
eject Stops a CD-ROM and then ejects its caddy
erase Performs erase operations on a device
exit Exit the scu program. Ctrl/d can be used in interactive
operation. An alias for exit is quit.
evaluate Evaluates an expression
format Formats disk media
help Displays help on scu command elements
mbad Produces hard and soft errors on disks
mt Issues one of the supported magnetic tape commands
onerror Controls program actions when an error occurs
pause Pauses playing a CD-ROM audio disk
play Plays tracks on a CD-ROM audio disk
prevent Prevents removal of media from a device
read Performs read operations on a device
reassign Reassigns a defective block on a disk device
release Releases a reserved device or a frozen SIM queue
repeat Defines a repeat count for a series of commands
reserve Reserves a device for exclusive use
resume Resumes playing a paused CD-ROM audio disk
reset Resets a bus or device
rezero Issues a CAM Bus Reset CCB command
scan Scans device media or the CAM Equipment Device Table
(EDT)
seek Seeks a logical block address
set Sets parameters for a device or the scu program
shell Exits to shell program until you exit the shell
show Displays parameters for a device or the scu program
sleep Specifies the time the scu program is to sleep
source Sources input from an external command file
start Starts a unit that is stopped
stop Stops a unit
switch Switches to another device
system Passes one system command to the shell program
test Performs tests on a controller
time Times command sequences
tur Issues a Test Unit Ready command to a device
usleep Specifies the time the scu program is to sleep (in
microseconds).
verify Performs verify operations on a device
write Performs write operations on a device
xza Performs operations on the KZMSA controller
zero Zeros device or scu program parameters
------------------------------------------------------------------
Commands that modify device data or device parameters
require write access to the device entry. Applications
that change the volume level of the CD-ROM must open the
device for write access since a SCSI Mode Select command
is used to modify the volume level.
Success. Warning. Failure.
When a SCSI device error occurs, both the sense key and
the addition sense code or qualifier are decoded and displayed
as follows: scu: Sense Key = 0x5 = ILLEGAL REQUEST
- Illegal request or CDB parameter,
Sense Code/Qualifier = (0x20, 0) = Invalid command
operation code
This error indicates that you have issued a command that
is not supported by the selected device. This can happen
for optional commands that are not supported by all
devices.
To format an RX26 diskette at extra density, enter: scu>
format density ED To verify 1024 blocks starting at block
1000, enter: scu> verify media starting 1000 length 1024
To display all changeable mode pages for a device, enter:
scu> show page pcf changeable To display inquiry information
for all devices on the first SCSI bus at lun 0 in the
Equipment Device Table (EDT), enter: scu> show edt bus 0
lun 0 full
The SCSI Utility executable file. The device entry for
the CAM User Agent driver. Contains the scu help information.
Is the location of the raw device special files for
hard disk devices.
Commands: file(1), more(1)
Functions: open(2), close(2), ioctl(2), fopen(3),
fgets(3), fputs(3), popen(3), pclose(3), malloc(3),
printf(3), fprintf(3)
American National Standard for Information Systems, Small
Computer Systems Interface - 2 (SCSI - 2), X3.131-199X
American National Standard for Information Systems, SCSI-2
Common Access Method: Transport and SCSI Interface Module,
working draft, X3T9.2/90-186
scu(8)
[ Back ] |
