man camcontrol for freebsd

CAMCONTROL(8)  FreeBSD System Manager's Manual   CAMCONTROL(8)

NAME
     camcontrol - CAM control program

SYNOPSIS
     camcontrol <command> [device id] [generic args] [command args]
     camcontrol devlist [-v]
     camcontrol periphlist [device id] [-n dev_name] [-u unit_number]
     camcontrol tur [device id] [generic args]
     camcontrol inquiry [device id] [generic args] [-D] [-S] [-R]
     camcontrol start [device id] [generic args]
     camcontrol stop [device id] [generic args]
     camcontrol eject [device id] [generic args]
     camcontrol rescan <bus[:target:lun]>
     camcontrol reset <bus[:target:lun]>
     camcontrol defects [device id] [generic args] <-f format> [-P] [-G]
     camcontrol modepage [device id] [generic args] <-m page> [-P pgctl] [-e]
  [-d]
     camcontrol cmd [device id] [generic args] <-c cmd [args]> [-i len fmt]
  [-o len fmt [args]]
     camcontrol debug [-I] [-T] [-S] [-c] <all|off|bus[:target[:lun]]>
     camcontrol tags [device id] [generic args] [-N tags] [-q] [-v]
     camcontrol negotiate [device id] [generic args] [-c] [-D enable|disable]
  [-O offset] [-q] [-R syncrate] [-T enable|disable] [-U] [-W
  bus_width] [-v]
     camcontrol format [device id] [generic args] [-q] [-w] [-y]
     camcontrol help

DESCRIPTION
     camcontrol is a utility designed to provide a way for users to access and
     control the FreeBSD CAM subsystem.

     camcontrol can cause a loss of data and/or system crashes if used improp-
     erly.  Even expert users are encouraged to exercise caution when using
     this command.  Novice users should stay away from this utility.

     camcontrol has a number of primary functions, many of which support an
     optional device identifier.  A device identifier can take one of three
     forms:

     deviceUNIT      Specify a device name and unit number combination, like
       "da5" or "cd3".  Note that character device node names
       (e.g. /dev/rsd0.ctl) are not allowed here.

     bus:target      Specify a bus number and target id.  The bus number can
       be determined from the output of ``camcontrol devlist''.
       The lun defaults to 0.

     bus:target:lun  Specify the bus, target and lun for a device.  (e.g.
       1:2:0)

     The device identifier, if it is specified, must come immediately after
     the function name, and before any generic or function-specific arguments.
     Note that the -n and -u arguments described below will override any de-
     vice name or unit number specified beforehand.  The -n and -u arguments
     will not override a specified bus:target or bus:target:lun, however.

     Most of the camcontrol primary functions support these generic arguments:

     -C count      SCSI command retry count. In order for this to work, er-
       ror recovery (-E) must be turned on.

     -E       Instruct the kernel to perform generic SCSI error recov-
       ery for the given command.  This is needed in order for
       the retry count (-C) to be honored.  Other than retrying
       commands, the generic error recovery in the code will
       generally attempt to spin up drives that are not spin-
       ning.  It may take some other actions, depending upon the
       sense code returned from the command.

     -n dev_name     Specify the device type to operate on, e.g. "da", "cd".

     -t timeout      SCSI command timeout in seconds.  This overrides the de-
       fault timeout for any given command.

     -u unit_number  Specify the device unit number, e.g. "1", "5".

     -v       Be verbose, print out sense information for failed SCSI
       commands.

     Primary command functions:

     devlist  List all physical devices (logical units) attached to the CAM
   subsystem.  This also includes a list of peripheral drivers
   attached to each device.  With the -v argument, SCSI bus num-
   ber, adapter name and unit numbers are printed as well.

     periphlist  List all peripheral drivers attached to a given physical de-
   vice (logical unit).

     tur  Send the SCSI test unit ready (0x00) command to the given de-
   vice. camcontrol will report whether the device is ready or
   not.

     inquiry  Send a SCSI inquiry command (0x12) to a device.  By default,
   camcontrol will print out the standard inquiry data, device
   serial number, and transfer rate information. The user can
   specify that only certain types of inquiry data be printed:

   -D    Get the standard inquiry data.

   -S    Print out the serial number.  If this flag is the only
         one specified, camcontrol will not print out "Serial
         Number" before the value returned by the drive. This
         is to aid in script writing.

   -R    Print out transfer rate information.

     start  Send the SCSI Start/Stop Unit (0x1B) command to the given de-
   vice with the start bit set.

     stop  Send the SCSI Start/Stop Unit (0x1B) command to the given de-
   vice with the start bit cleared.

     eject  Send the SCSI Start/Stop Unit (0x1B) command to the given de-
   vice with the start bit cleared and the eject bit set.

     rescan  Tell the kernel to scan the given bus (XPT_SCAN_BUS), or
   bus:target:lun (XPT_SCAN_LUN) for new devices or devices that
   have gone away.  The user may only specify a bus to scan, or
   a lun.  Scanning all luns on a target isn't supported.

     reset  Tell the kernel to reset the given bus (XPT_RESET_BUS) by is-
   suing a SCSI bus reset for that bus, or to reset the given
   bus:target:lun (XPT_RESET_DEV), typically by issuing a BUS
   DEVICE RESET message after connecting to that device. Note
   that this can have a destructive impact on the system.

     defects  Send the SCSI READ DEFECT DATA (10) command (0x37) to the
   given device, and print out any combination of: the total
   number of defects, the primary defect list (PLIST), and the
   grown defect list (GLIST).

   -f format    The three format options are: block, to print
         out the list as logical blocks, bfi, to print
         out the list in bytes from index format, and
         phys, to print out the list in physical sector
         format.  The format argument is required.  Most
         drives support the physical sector format.  Some
         drives support the logical block format. Many
         drives, if they don't support the requested for-
         mat, return the data in an alternate format,
         along with sense information indicating that the
         requested data format isn't supported.
         camcontrol attempts to detect this, and print
         out whatever format the drive returns.  If the
         drive uses a non-standard sense code to report
         that it doesn't support the requested format,
         camcontrol will probably see the error as a
         failure to complete the request.

   -G       Print out the grown defect list. This is a list
         of bad blocks that have been remapped since the
         disk left the factory.

   -P       Print out the primary defect list.

   If neither -P nor -G is specified, camcontrol will print out
   the number of defects given in the READ DEFECT DATA header
   returned from the drive.

     modepage  Allows the user to display and optionally edit a SCSI mode
   page. The mode page formats are located in
   /usr/share/misc/scsi_modes.  This can be overridden by speci-
   fying a different file in the SCSI_MODES environment vari-
   able. The modepage command takes several arguments:

   -d        Disable block descriptors for mode sense.

   -e        This flag allows the user to edit values in the
          mode page.

   -m mode_page  This specifies the number of the mode page the
          user would like to view and/or edit.  This ar-
          gument is mandatory.

   -P pgctl      This allows the user to specify the page con-
          trol field.  Possible values are:
          0    Current values
          1    Changeable values
          2    Default values
          3    Saved values

     cmd  Allows the user to send an arbitrary SCSI CDB to any device.
   The cmd function requires the -c argument to specify the CDB.
   Other arguments are optional, depending on the command type.
   The command and data specification syntax is documented in
   cam_cdbparse(3).  NOTE:  If the CDB specified causes data to
   be transfered to or from the SCSI device in question, you
   MUST specify either -i or -o.

   -c cmd [args]     This specifies the SCSI CDB.  CDBs may be
        6, 10, 12 or 16 bytes.

   -i len fmt     This specifies the amount of data to read,
        and how it should be displayed.  If the
        format is `-', len bytes of data will be
        read from the device and written to stan-
        dard output.

   -o len fmt [args]  This specifies the amount of data to be
        written to a device, and the data that is
        to be written.  If the format is `-', len
        bytes of data will be read from standard
        input and written to the device.

     debug  Turn on CAM debugging printfs in the kernel.  This requires
   options CAMDEBUG in your kernel config file.  WARNING:  en-
   abling debugging printfs currently causes an EXTREME number
   of kernel printfs.  You may have difficulty turning off the
   debugging printfs once they start, since the kernel will be
   busy printing messages and unable to service other requests
   quickly.  The debug function takes a number of arguments:

   -I       Enable CAM_DEBUG_INFO printfs.

   -T       Enable CAM_DEBUG_TRACE printfs.

   -S       Enable CAM_DEBUG_SUBTRACE printfs.

   -c       Enable CAM_DEBUG_CDB printfs.  This will
         cause the kernel to print out the SCSI
         CDBs sent to the specified device(s).

   all       Enable debugging for all devices.

   off       Turn off debugging for all devices

   bus[:target[:lun]]  Turn on debugging for the given bus, tar-
         get or lun.  If the lun or target and lun
         are not specified, they are wildcarded.
         (i.e., just specifying a bus turns on de-
         bugging printfs for all devices on that
         bus.)

     tags  Show or set the number of "tagged openings" or simultaneous
   transactions we attempt to queue to a particular device.  By
   default, the tags command, with no command-specific arguments
   (i.e. only generic arguments) prints out the "soft" maximum
   number of transactions that can be queued to the device in
   question.  For more detailed information, use the -v argument
   described below.

   -N tags  Set the number of tags for the given device. This
     must be between the minimum and maximum number set
     in the kernel quirk table.  The default for most de-
     vices that support tagged queueing is a minimum of 2
     and a maximum of 255.  The minimum and maximum val-
     ues for a given device may be determined by using
     the -v switch.  The meaning of the -v switch for
     this camcontrol subcommand is described below.

   -q   Be quiet, and don't report the number of tags.  This
     is generally used when setting the number of tags.

   -v   The verbose flag has special functionality for the
     tags argument.  It causes camcontrol to print out
     the tagged queueing related fields of the
     XPT_GDEV_TYPE CCB:

     dev_openings  This is the amount of capacity for
      transactions queued to a given de-
      vice.

     dev_active  This is the number of transactions
      currently queued to a device.

     devq_openings  This is the kernel queue space for
      transactions. This count usually
      mirrors dev_openings except during
      error recovery operations when the
      device queue is frozen (device is not
      allowed to receive commands), the
      number of dev_openings is reduced, or
      transaction replay is occurring.

     devq_queued  This is the number of transactions
      waiting in the kernel queue for ca-
      pacity on the device. This number is
      usually zero unless error recovery is
      in progress.

     held   The held count is the number of CCBs
      held by peripheral drivers that have
      either just been completed or are
      about to be released to the transport
      layer for service by a device.  Held
      CCBs reserve capacity on a given de-
      vice.

     mintags  This is the current "hard" minimum
      number of transactions that can be
      queued to a device at once.  The
      dev_openings value above cannot go
      below this number.  The default value
      for mintags is 2, although it may be
      set higher or lower for various de-
      vices.

     maxtags  This is the "hard" maximum number of
      transactions that can be queued to a
      device at one time.  The dev_openings
      value cannot go above this number.
      The default value for maxtags is 255,
      although it may be set higher or low-
      er for various devices.

     negotiate  Show or negotiate various communication parameters.  Some
   controllers may not support setting or changing some of these
   values.  For instance, the Adaptec 174x controllers do not
   support changing a device's sync rate or offset.  camcontrol
   will not attempt to set the parameter if the controller indi-
   cates that it does not support setting the parameter. To
   find out what the controller supports, use the -v flag.  The
   meaning of the -v flag for the negotiate command is described
   below.  Also, some controller drivers don't support setting
   negotiation parameters, even if the underlying controller
   supports negotiation changes. Some controllers, such as the
   Advansys wide controllers, support enabling and disabling
   synchronous negotiation for a device, but do not support set-
   ting the synchronous negotiation rate.

   -a      Attempt to make the negotiation settings
        take effect immediately by sending a Test
        Unit Ready command to the device.

   -c      Show or set current negotiation settings.
        This is the default.

   -D enable|disable  Enable or disable disconnection.

   -O offset     Set the command delay offset.

   -q      Be quiet, don't print anything.  This is
        generally useful when you want to set a
        parameter, but don't want any status in-
        formation.

   -R syncrate     Change the synchronization rate for a de-
        vice.  The sync rate is a floating point
        value specified in MHz.  So, for instance,
        `20.000' is a legal value, as is `20'.

   -T enable|disable  Enable or disable tagged queueing for a
        device.

   -U      Show or set user negotiation settings.
        The default is to show or set current ne-
        gotiation settings.

   -v      The verbose switch has special meaning for
        the negotiate subcommand.  It causes
        camcontrol to print out the contents of a
        Path Inquiry (XPT_PATH_INQ) CCB sent to
        the controller driver.

   -W bus_width     Specify the bus width to negotiate with a
        device.  The bus width is specified in
        bits.  The only useful values to specify
        are 8, 16, and 32 bits.  The controller
        must support the bus width in question in
        order for the setting to take effect.

   In general, sync rate and offset settings will not take ef-
   fect for a device until a command has been sent to the de-
   vice. The -a switch above will automatically send a Test
   Unit Ready to the device so negotiation parameters will take
   effect.

     format  Issue the SCSI FORMAT UNIT command to the named device.

   WARNING! WARNING! WARNING!

   Low level formatting a disk will destroy ALL data on the
   disk. Use extreme caution when issuing this command. Many
   users low-level format disks that do not really need to be
   low-level formatted.  There are relatively few scenarios that
   call for low-level formatting a disk. One reason for low-
   level formatting a disk is to initialize the disk after
   changing its physical sector size.  Another reason for low-
   level formatting a disk is to revive the disk if you are get-
   ting "medium format corrupted" errors from the disk in re-
   sponse to read and write requests.

   Some disks take longer than others to format. Users should
   specify a timeout long enough to allow the format to com-
   plete.  The default format timeout is 3 hours, which should
   be long enough for most disks.  Some hard disks will complete
   a format operation in a very short period of time (on the or-
   der of 5 minutes or less).  This is often because the drive
   doesn't really support the FORMAT UNIT command -- it just ac-
   cepts the command, waits a few minutes and then returns it.

   The `format' subcommand takes several arguments that modify
   its default behavior. The -q and -y arguments can be useful
   for scripts.

   -q  Be quiet, don't print any status messages.  This op-
    tion will not disable the questions, however. To
    disable questions, use the -y argument, below.

   -w  Issue a non-immediate format command. By default,
    camcontrol issues the FORMAT UNIT command with the
    immediate bit set.  This tells the device to immedi-
    ately return the format command, before the format
    has actually completed.  Then, camcontrol gathers
    SCSI sense information from the device every second
    to determine how far along in the format process it
    is.  If the -w argument is specified, camcontrol will
    issue a non-immediate format command, and will be un-
    able to print any information to let the user know
    what percentage of the disk has been formatted.

   -y  Don't ask any questions.  By default, camcontrol will
    ask the user if he/she really wants to format the
    disk in question, and also if the default format com-
    mand timeout is acceptable.  The user will not be
    asked about the timeout if a timeout is specified on
    the command line.

     help  Print out verbose usage information.

ENVIRONMENT
     The SCSI_MODES variable allows the user to specify an alternate mode page
     format file.

     The EDITOR variable determines which text editor camcontrol starts when
     editing mode pages.

FILES
     /usr/share/misc/scsi_modes  is the SCSI mode format database.
     /dev/xpt0    is the transport layer device.
     /dev/pass*    are the CAM application passthrough devices.

EXAMPLES
    camcontrol eject -n cd -u 1 -v

     Eject the CD from cd1, and print SCSI sense information if the command
     fails.

    camcontrol tur da0

     Send the SCSI test unit ready command to da0.  camcontrol will report
     whether the disk is ready, but will not display sense information if the
     command fails since the -v switch was not specified.

    camcontrol tur da1 -E -C 4 -t 50 -v

     Send a test unit ready command to da1.  Enable kernel error recovery.
     Specify a retry count of 4, and a timeout of 50 seconds.  Enable sense
     printing (with the -v flag) if the command fails. Since error recovery
     is turned on, the disk will be spun up if it is not currently spinning.
     camcontrol will report whether the disk is ready.

    camcontrol cmd -n cd -u 1 -v -c "3C 00 00 00 00 00 00 00 0e 00" \
     -i 0xe "s1 i3 i1 i1 i1 i1 i1 i1 i1 i1 i1 i1"

     Issue a READ BUFFER command (0x3C) to cd1.  Display the buffer size of
     cd1, and display the first 10 bytes from the cache on cd1.  Display SCSI
     sense information if the command fails.

    camcontrol cmd -n cd -u 1 -v -c "3B 00 00 00 00 00 00 00 0e 00" \
     -o 14 "00 00 00 00 1 2 3 4 5 6 v v v v" 7 8 9 8

     Issue a WRITE BUFFER (0x3B) command to cd1.  Write out 10 bytes of data,
     not including the (reserved) 4 byte header.  Print out sense information
     if the command fails.  Be very careful with this command, improper use
     may cause data corruption.

    camcontrol modepage da3 -m 1 -e -P 3

     Edit mode page 1 (the Read-Write Error Recover page) for da3, and save
     the settings on the drive.  Mode page 1 contains a disk drive's auto read
     and write reallocation settings, among other things.

    camcontrol rescan 0

     Rescan SCSI bus 0 for devices that have been added, removed or changed.

    camcontrol rescan 0:1:0

     Rescan SCSI bus 0, target 1, lun 0 to see if it has been added, removed,
     or changed.

    camcontrol tags da5 -N 24

     Set the number of concurrent transactions for da5 to 24.

    camcontrol negotiate -n da -u 4 -T disable

     Disable tagged queueing for da4.

    camcontrol negotiate -n da -u 3 -R 20.000 -O 15 -a

     Negotiate a sync rate of 20MHz and an offset of 15 with da3.  Then send a
     Test Unit Ready command to make the settings take effect.

SEE ALSO
     cam(3), cam_cdbparse(3), cam(4), pass(4), xpt(4)

HISTORY
     The camcontrol command first appeared in FreeBSD 3.0.

     The mode page editing code and arbitrary SCSI command code are based upon
     code in the old scsi(8) utility and scsi(3) library, written by Julian
     Elischer and Peter Dufault.  The scsi(8) program first appeared in 386BSD
     0.1.2.4, and first appeared in FreeBSD in FreeBSD 2.0.5.

AUTHORS
     Kenneth Merry <[email protected]>

BUGS
     The code that parses the generic command line arguments doesn't know that
     some of the subcommands take multiple arguments.  So if, for instance,
     you tried something like this:

    camcontrol cmd -n da -u 1 -c "00 00 00 00 00 v" 0x00 -v

     The sense information from the test unit ready command would not get
     printed out, since the first getopt(3) call in camcontrol bails out when
     it sees the second argument to -c (0x00), above.  Fixing this behavior
     would take some gross code, or changes to the getopt(3) interface.  The
     best way to circumvent this problem is to always make sure to specify
     generic camcontrol arguments before any command-specific arguments.

BSD         September 14, 1998        8