Provided by: sg3-utils_1.46-3ubuntu2.1_amd64 bug

NAME

       sg_modes - reads mode pages with SCSI MODE SENSE command

SYNOPSIS

       sg_modes  [--all]  [--control=PC]  [--dbd]  [--dbout]  [--examine]  [--flexible]  [--help]
       [--hex] [--list] [--llbaa] [--maxlen=LEN]  [--page=PG[,SPG]]  [--raw]  [-R]  [--readwrite]
       [--six] [--verbose] [--version] [DEVICE]

       sg_modes  [-6]  [-a]  [-A]  [-c=PC]  [-d]  [-D]  [-e]  [-f]  [-h]  [-H] [-l] [-L] [-m=LEN]
       [-p=PG[,SPG]] [-r] [-subp=SPG] [-v] [-V] [-w] [-?] [DEVICE]

DESCRIPTION

       This utility sends a MODE SENSE SCSI command to the DEVICE and outputs the response. There
       is  a 6 byte and 10 byte (cdb) variant of the MODE SENSE command, this utility defaults to
       the 10 byte variant. The SPC-4 standard (and SPC-5 drafts) include  a  note  stating  that
       implementers  should  migrate away from the SCSI MODE SELECT(6) and MODE SENSE(6) commands
       in favour of the 10 byte variants (e.g. MODE SENSE(10)).

       This utility decodes mode page headers and block descriptors but outputs the  contents  of
       each  mode  page in hex. It also has no facility to change the mode page contents or block
       descriptor data. Mode page contents are decoded and can be changed by the sdparm utility.

       This utility supports two command line syntaxes, the preferred one is shown first  in  the
       synopsis  and  explained  in  this section. A later section on the old command line syntax
       outlines the second group of options.

       If no page is given (and --list is not selected) then --all is assumed. The  --all  option
       requests all mode pages (but not subpages) in a single response.

OPTIONS

       Arguments to long options are mandatory for short options as well.

       -a, --all
              output  all  the  mode  pages reported by the DEVICE. This is what the page code 63
              (0x3f) is defined to do. When used once, mode subpages are not fetched.  When  used
              twice  (e.g.  '-aa'), all mode pages and subpages are requested which is equivalent
              to '--page=63,255'.

       -c, --control=PC
              PC is the page control value. Up to four different versions of each page  are  held
              by the device:
                0 : current values (i.e. those active at present)
                1 : changeable values
                2 : default values (i.e. the manufacturer's settings)
                3 : saved values
              The  changeable  values  are bit masks showing which fields could be changed with a
              MODE SELECT. The saved values will be re-instated the next time the device is power
              cycled or reset. If this option is not given then current values [0] are assumed.

       -d, --dbd
              disable  block  descriptors. By default, block descriptors (usually one (for disks)
              or none) are returned in a MODE SENSE response. This option sets the "disable block
              descriptors"  (DBD)  bit  in  the  cdb which instructs the device not to return any
              block descriptors in its response. Older devices may not support this  setting  and
              may  return an "illegal request" sense key; alternatively they may ignore it. Oddly
              the Reduced Block Command set (RBC) requires this bit set.

       -D, --dbout
              disable outputting block descriptors. Irrespective of whether block descriptors are
              present in the response or not, they are not output.

       -e, --examine
              examine  each mode page in the range 0 through to 62 (inclusive).  If some response
              is given then print out the mode page name or number (in hex) if the  name  is  not
              known.
              The  sdparm utility which lists mode and VPD pages also has a --examine option will
              similar functionility.

       -f, --flexible
              Some devices, bridges and/or drivers attempt crude translations between MODE  SENSE
              6  and  10  byte  commands  without  correcting  the  response. This will cause the
              response to be mis-interpreted (usually  with  an  error  saying  the  response  is
              malformed).  With  this  option,  the  length of the response is checked, and if it
              looks wrong, the response is then decoded as if the other mode sense  (cdb  length)
              was sent.

       -h, --help
              print out the usage message then exit.

       -H, --hex
              The  default action is to decode known mode page numbers (and subpage numbers) into
              text. When this option is used once, the  response  is  output  in  hexadecimal  to
              stdout.  When  this option is used twice, mode page numbers and page control values
              are output in hex.
              When this option is used three times, the full response to the MODE  SENSE  command
              is  output  in hex to stdout without any decoding. This form can be redirected to a
              file (or piped) and then used 'sdparm --inhex=' to decode.

       -l, --list
              lists all common page and subpage codes and their  names  that  are  found  in  the
              command set that matches the peripheral type of the given DEVICE.  If no DEVICE and
              no --page=PG is given then the common page and subpage codes and  their  names  are
              listed  for  SBC (e.g. a disk). If no DEVICE is given and a --page=PG is given then
              the common page and subpage codes and their names are listed for  the  command  set
              whose  peripheral  device  type matches the value given to PG. For example 'sg_mode
              --list --page=1' lists the command  mode  pages  and  subpages  for  tape  devices.
              Additionally  if  a  sub_page_code  is  given then it is interpreted as a transport
              identifier and command transport specific mode  page  codes  and  their  names  are
              listed following the main mode page list.  Other options are ignored.

       -L, --llbaa
              set  the  Long LBA Accepted (LLBAA) bit in the MODE SENSE (10) cdb. This bit is not
              defined in the MODE SENSE (6) cdb so  setting  the  '-L'  and  '--six'  options  is
              reported  as  an  error.  When  set  the  DEVICE  may  respond  with  16 byte block
              descriptors as indicated by the 'LongLBA' field in  the  response.  In  most  cases
              setting this option is not needed.

       -m, --maxlen=LEN
              The  LEN  argument  is  the maximum response length in bytes. It is the 'allocation
              length' field in the cdb. When not given (or  LEN  is  zero)  then  the  allocation
              length  field is set to 4096 for MODE SENSE (10) or 252 for MODE SENSE (6). The LEN
              argument must be non-negative and no greater than 65535 for MODE SENSE (10) and not
              greater than 255 for MODE SENSE (6).

       -O, --old
              Switch to older style options. Please use as first option.

       -p, --page=PG
              page code to fetch. The PG is assumed to be a decimal value unless prefixed by '0x'
              or has a trailing 'h'. It should be a value between 0 and 63 (inclusive). When  not
              given  and  a default is required then a value of 63 (0x3f), which fetches all mode
              pages, is used.
              Alternatively an acronym for the mode page can be given. The available acronyms can
              be  listed out with the --page=xxx option. They are almost the same as the acronyms
              used for mode pages in the sdparm utility.

       -p, --page=PG,SPG
              page code and subpage code values to  fetch.  Both  arguments  are  assumed  to  be
              decimal  unless  flagged  as  hexadecimal. The page code should be between 0 and 63
              inclusive. The subpage code should be between 0  and  255  inclusive.  The  default
              value for the subpage code is 0.

       -r, --raw
              output  the  response in binary to stdout. Error messages and warnings, if any, are
              sent to stderr. When this option is used twice  (e.g.  '-rr')  then  has  the  same
              action as '-R'

       -R     output  the  selected  mode  page to stdout a byte per line. Each line contains two
              hexadecimal  digits  (e.g.  "3e").  Useful  as  input  (after   editing)   to   the
              sg_wr_mode(8) utility.

       -w, --readwrite
              open DEVICE in "read-write" mode. Default is to open it in read-only mode.

       -6, -s, --six
              by  default  this utility sends a 10 byte MODE SENSE command to the DEVICE. However
              some SCSI devices only support  6  byte  MODE  SENSE  commands  (e.g.  SCSI-2  tape
              drives). This parameter forces the use of 6 byte MODE SENSE commands.

       -v, --verbose
              increase level of verbosity. Can be used multiple times.

       -V, --version
              print out version string then exit.

NOTES

       If  the  normal  sg_modes utility fails with "illegal command operation code" then try the
       '--six' (or '-6') option.

       This utility performs a SCSI INQUIRY command to  determine  the  peripheral  type  of  the
       device (e.g. 0 -> Direct Access Device (disk)) prior to sending a MODE SENSE command. This
       helps in decoding the block descriptor and mode pages.

       This utility opens DEVICE in read-only mode (e.g. in Unix,  with  the  O_RDONLY  flag)  by
       default. It will open DEVICE in read-write mode if the --readwrite option is given.

       In  the  2.4 series of Linux kernels the DEVICE must be a SCSI generic (sg) device. In the
       2.6 series block devices (e.g. SCSI disks and DVD  drives)  can  also  be  specified.  For
       example "sg_modes -a /dev/sda" will work in the 2.6 series kernels.

EXIT STATUS

       The exit status of sg_modes is 0 when it is successful. Otherwise see the sg3_utils(8) man
       page.

OLDER COMMAND LINE OPTIONS

       The options in this section were the only ones available prior to sg3_utils version 1.23 .
       Since then this utility defaults to the newer command line options which can be overridden
       by using --old (or -O) as the first option. See  the  ENVIRONMENT  VARIABLES  section  for
       another way to force the use of these older command line options.

       -6     by  default  this  utility  sends  a 10 byte MODE SENSE command to the DEVICE. This
              parameter forces the use of 6 byte MODE SENSE commands.   See  --six  in  the  main
              description.

       -a     see --all in the main description.

       -A     output  all  the  mode  pages  and subpages supported by the DEVICE. Same as '--all
              --all' in the new syntax.

       -c=PC  PC is the page control value. See --control=PC in the main description.

       -d     see --dbd in the main description.

       -D     see --dbout in the main description.

       -e     see --examine in the main description.

       -f     see --flexible in the main description.

       -h     The default action is to decode known mode page numbers (and subpage numbers)  into
              text.  With  this  option  mode  page  numbers  (and subpage numbers) are output in
              hexadecimal.

       -H     same action as the '-h' option.

       -l     see --list in the main description.

       -L     see --llbaa in the main description.

       -N, --new
              Switch to the newer style options.

       -m=LEN see --maxlen=LEN in the main description.

       -p=PG  PG is page code to fetch. Should be a hexadecimal number between 0 and 3f inclusive
              (0  to  63  decimal). The default value when required is 3f (fetch all mode pages).
              Note that an acronym for the page and/or subpage values is  not  accepted  in  this
              older  format  (because  any  acronym  starting  with  the  letters  'a'  to 'f' is
              ambiguous; it could either be a hex number or an acronym).

       -p=PG,SPG
              page code and subpage code values to fetch. The page code should be  a  hexadecimal
              number  between 0 and 3f inclusive. The subpage code should be a hexadecimal number
              between 0 and ff inclusive. The default value for the subpage code is 0.

       -r     output the selected mode page to stdout a byte per line.  Each  line  contains  two
              hexadecimal   digits   (e.g.   "3e").  Useful  as  input  (after  editing)  to  the
              sg_wr_mode(8) utility.

       -subp=SPG
              sub page code to  fetch.  Should  be  a  hexadecimal  number  between  0  and  0xff
              inclusive. The default value is 0.

       -v     increase verbosity of output.

       -V     print out version string then exit.

       -w     see --readwrite in the main description.

       -?     output usage message then exit. Ignore all other parameters.

ENVIRONMENT VARIABLES

       Since  sg3_utils  version  1.23  the environment variable SG3_UTILS_OLD_OPTS can be given.
       When it is present this utility will  expect  the  older  command  line  options.  So  the
       presence  of  this  environment variable is equivalent to using --old (or -O) as the first
       command line option.

AUTHOR

       Written by Douglas Gilbert

REPORTING BUGS

       Report bugs to <dgilbert at interlog dot com>.

COPYRIGHT

       Copyright © 2000-2020 Douglas Gilbert
       This software is distributed under the GPL version 2. There is NO warranty; not  even  for
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO

       sdparm(8),   sg_wr_mode(8),   sginfo(8),  sgmode(scsirastools),  scsiinfo(net),  scu(net),
       seatools(seagate)

       All these utilities offer  some  facility  to  change  mode  page  (or  block  descriptor)
       parameters.