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  man pages->Tru64 Unix man pages -> scu (8)              



NAME    [Toc]    [Back]

       scu - SCSI CAM Utility Program

SYNOPSIS    [Toc]    [Back]

       /sbin/scu [-options ...] [command [keywords...]]

OPTIONS    [Toc]    [Back]

       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.

DESCRIPTION    [Toc]    [Back]

       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.


       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

       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

COMMANDS    [Toc]    [Back]

       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
       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
       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

RESTRICTIONS    [Toc]    [Back]

       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.

EXIT STATUS    [Toc]    [Back]

       Success.  Warning.  Failure.

ERRORS    [Toc]    [Back]

       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

EXAMPLES    [Toc]    [Back]

       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

FILES    [Toc]    [Back]

       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.

SEE ALSO    [Toc]    [Back]

       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

[ Back ]
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