scu - SCSI CAM Utility Program
/sbin/scu [ -options... ] [ command [ keywords... ]]
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.
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.
Specifies the user agent path. Specify the raw device pathname. You must specify a character device special file, for example, /dev/rrz3c.
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. Enable pipe operation mode. Specify a script startup file name.
The following table summarizes the scu commands and their functions. Refer to the help command for complete syntax and examples of use.
|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 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|
Scans device media or the CAM Equipment Device Table (EDT)
|seek||Seeks a logical block address|
Sets parameters for a device or the scu program
|shell||Exits to shell program until you exit the shell|
Displays parameters for a device or the scu program
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|
Specifies the time the scu program is to sleep (in
|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 CDROM must open the device for write access since a SCSI Mode Select command is used to modify the volume level.
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
For all commands, scu runs and exits with 0 for success, 1 for warning, or -1 for failure status.
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.
The SCSI Utility executable file. The device entry for the CAM User Agent driver. Contains the scu help information.
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 delim off