Provided by: sdparm_1.06-3build1_amd64 bug

NAME

       sdparm - access SCSI modes pages; read VPD pages; send simple SCSI commands.

SYNOPSIS

       sdparm  [--all]  [--clear=STR] [--command=CMD] [--dbd] [--defaults] [--dummy] [--flexible]
       [--get=STR] [--help] [--hex] [--inquiry] [--long] [--num-desc] [--page=PG[,SPG]] [--quiet]
       [--readonly]  [--save]  [--set=STR]  [--six]  [--transport=TN]  [--vendor=VN]  [--verbose]
       [--version] DEVICE [DEVICE...]

       sdparm  --enumerate  [--all]  [--inquiry]  [--long]   [--page=PG[,SPG]]   [--transport=TN]
       [--vendor=VN]

       sdparm --wscan [--verbose]

DESCRIPTION

       This  utility fetches and potentially changes SCSI device (e.g.  disk) mode pages. Inquiry
       data including Vital Product Data (VPD) pages can also be displayed.  Commands  associated
       with  starting  and  stopping  the  medium;  loading  and  unloading the medium; and other
       housekeeping function may also be issued by this utility.

       Of the three invocations shown in the synopsis, the first is the most general. The  second
       variant that uses --enumerate is for dumping information held in sdparm's internal tables.
       The last variant is for Windows only and lists the available device names; see the OPTIONS
       entry for --wscan.

       If  no  options  (other than DEVICE) are given then a selection of common mode page fields
       for that device are listed. If the --long option is also given then a description  of  the
       fields  is  placed  on the right of each line. If the --all option is given then all known
       mode page fields for that device are listed. Individual fields can be displayed  with  the
       --get=STR  option  (e.g.  '--get=WCE'  to  fetch  the  state of the Writeback Cache Enable
       field).

       This utility completes with an exit status of 0 when successful. For other values see  the
       EXIT STATUS section below.

       One  or  more  DEVICE arguments can be given. The utility will essentially apply the given
       options to each DEVICE in the list.  If an error is detected, it is noted and the  utility
       continues.   Error  value 5 (file open or close problem) is treated as lower priority when
       other errors are detected. The exit status is  the  most  recently  detected  error  value
       (excluding  error  value 5 if other errors have been detected). If all actions succeed the
       exit status is zero.

       By default this utility shows mode pages that are common to all transport protocols. These
       are  termed  as "generic" mode pages.  If there is no match on a generic mode page name or
       field then those pages specific to the SAS  transport  are  checked.   Transport  protocol
       specific mode pages are selected with the --transport=TN option. See the TRANSPORT section
       below.  Vendor specific mode pages are selected with  the  --vendor=VN  option.   See  the
       VENDORS section below.

       Although  originally  for  SCSI  disks  (or  storage devices that appear to the OS as SCSI
       disks) many of the mode pages are for other  SCSI  device  types.   These  include  CD/DVD
       players  that  use  the  ATAPI  (or  any  other)  transport,  SCSI  tapes  drives and SCSI
       enclosures.

       When the --inquiry option is given without a page number then  the  Device  Identification
       VPD page (page number 0x83) is requested and if found it is decoded and output. If no page
       number is given and the --all option is given then a list of VPD page names (but not their
       contents) supported by the DEVICE is output. When both the --inquiry and --page=PG options
       are given then the VPD page can be specified as an abbreviation (e.g. "sp"  for  the  SCSI
       ports  VPD page) or numerically (e.g. "0x88"). If a VPD page is returned by the DEVICE but
       sdparm cannot decode it or the --hex option is given then it is output in hex.

OPTIONS

       Mandatory arguments to long options are mandatory for short options as well.  If an option
       takes  a  numeric  argument  then  that argument is assumed to be decimal unless otherwise
       indicated (e.g. with a leading "0x" or a trailing "h"). The options  are  in  alphabetical
       order, based on the long option name.

       -a, --all
              output all recognized fields for the device type (e.g. disk) of the DEVICE. Without
              this option (or the --page=PG[,SPG] option) the  default  action  is  to  output  a
              relatively  small  number  of  commonly  used  fields  from different pages. When a
              specific (mode) page number is given with the --page=PG[,SPG] option then  all  the
              fields  of  that  page are output (irrespective of the setting of this option). For
              this option's action when used  with  the  --enumerate  option  see  the  ENUMERATE
              section below.

       -c, --clear=STR
              In  its  simplest  form  STR  contains  a  field  acronym_name or a field numerical
              descriptor. In the absence of an explicit value  argument  (e.g.  '--clear=WCE=1'),
              the field has its value cleared to zero.  See the PARAMETERS section below.

       -C, --command=CMD
              Perform  given  CMD. See section below on COMMANDS. To enumerate supported commands
              use '-e -C x' (using any CMD name, valid or otherwise).

       -B, --dbd
              disable block descriptors. This is a bit in MODE SENSE cdbs that rarely needs to be
              set.  One  known  case  is  a MODE SENSE 6 issued to a Reduced Block Commands (RBC)
              device where the RBC standard says it shall be set.

       -D, --defaults
              sets the given mode page to its default values. Requires the --page=PG[,SPG] option
              to be given to specify the mode page. To make the default mode page values also the
              saved mode page values, use the --save option as well.

       -d, --dummy
              when set inhibits changes being placed in the DEVICE's mode page.  Instead the mode
              data  that would have been sent to a MODE SELECT command, is output in ASCII hex to
              the console. This option is mainly for testing.

       -e, --enumerate
              lists out descriptive information about the pages and fields known to this utility.
              Ignores  the  DEVICE  argument  and  other options apart from the --all, --inquiry,
              --long, --page=PG[,SPG], --transport=TN and --vendor=VN. If  --enumerate  is  given
              without  other  options  then  the  known (generic) mode pages are listed.  See the
              ENUMERATE section below.

       -f, --flexible
              Some devices, bridges and/or drivers attempt  crude  transformations  between  mode
              sense  6 and 10 byte commands without correctly rebuilding 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, various corrections are attempted. This option will  also  allow  mode
              pages that don't belong to the current device's peripheral type to be listed.

       -g, --get=STR
              In  its  simplest  form  STR  contains  a  field  acronym_name or a field numerical
              descriptor. The field is fetched from mode page. See the PARAMETERS section  below.
              The  --long  and  --hex options effect the output format. Also if a value of "1" is
              given (e.g. '--get=WCE=1') only the current value is output (i.e.  not  the  change
              mask, the default value and the saved value).

       -h, --help
              output the usage message then exit.

       -H, --hex
              rather  than trying to decode mode (or VPD) pages, print them out in hex. When used
              with the --get=STR option the corresponding current, changeable, default and  saved
              values  are  output in hex, prefixed by "0x" and space separated. If a value of "1"
              is given with the --get=STR option (e.g. '--get=WCE=1') then only the current value
              is  output  in hex, prefixed by "0x". If a value of "2" is given with the --get=STR
              option then only the current value is output as a (signed) integer. This option can
              be used multiple times (e.g. '-HH'). Useful with the ATA Information VPD page which
              usually outputs its IDENTIFY (PACKET) DEVICE response in 16  bit  hex  words;  with
              '-HH'  outputs that response in hex bytes; with '-HHH' outputs the same response in
              a format suitable for 'hdparm --Istdin' to decode.

       -i, --inquiry
              output INQUIRY VPD pages. In the absence of this option the default  action  is  to
              output  mode  pages.  If  the --inquiry option is given without the --page=PG[,SPG]
              option then the device identification VPD page (0x83) is  decoded  and  output.  If
              this  option and the --all option are given then the supported VPD pages page (0x0)
              is decoded and output.

       -l, --long
              output extra information. In the case of mode page fields a description (with units
              if  applicable)  is  output  to the right. If used twice, then for some fields more
              information about its values is given on one or more following lines, each prefixed
              by a tab character. For usage with --enumerate see the ENUMERATE section below.

       -n, --num-desc
              for  a mode page that can have descriptors, the number of descriptors for the given
              page on the DEVICE is output. Otherwise 0 is output.

       -p, --page=PG[,SPG]
              supply the page number (PG) and optionally the sub page number (SPG)  of  the  mode
              (or  VPD)  page  to fetch. These numbers are interpreted as decimal unless prefixed
              with "0x" or a trailing. Sub page numbers are only valid for mode  pages  (not  VPD
              pages). Alternatively an abbreviation for a page can be given (see next entry).

       -p, --page=STR
              a  two  or  three  letter  abbreviation  for  a  page can be given. Known mode page
              abbreviations are checked first followed by  known  VPD  page  abbreviations.   For
              example  '--page=ca'  matches  the  caching mode page. If no match is found then an
              error is issued and a list of possibilities in the current context is given (so '-p
              x'  can be quite useful). If the STR matches a known VPD page abbreviation then the
              --inquiry option is assumed. For usage with --enumerate see the  ENUMERATE  section
              below.

       -q, --quiet
              suppress output of device name followed by the vendor, product and revision strings
              fetched from an INQUIRY response. Without this option such a line is typically  the
              first  line  output  by  sdparm.  Reduces output from the device identification VPD
              page, typically to one line (or none) for each of  di_lu,  di_port,  di_target  and
              di_asis.

       -r, --readonly
              override other logic to open DEVICE in read-only mode. This option may be useful if
              a command is being sent to an ATA disk via a SCSI command set. For example in Linux
              '-C stop' may require this option to stop an ATA disk being restarted immediately.

       -S, --save
              when  a  mode  page  is  being  modified (by using the --clear=STR and/or --set=STR
              options) then the default action is to modify only the current  values  mode  page.
              When  this option is given then the corresponding value(s) in the saved values mode
              page is also changed. The next time the device is power cycled (or reset) the saved
              values  mode  page  becomes  (i.e.  is copied to) the current values mode page. See
              NOTES section below.

       -s, --set=STR
              in its simplest form STR  contains  a  field  acronym_name  or  a  field  numerical
              descriptor.  In  the  absence of an explicit value, each acronym_name has its value
              set to (all) ones. This means a 16 bit field will be set to 0xffff which  is  65535
              in decimal. Alternatively each acronym_name or numerical descriptor may be followed
              by "=<n>" where <n> is the value to set that field to. See the  PARAMETERS  section
              below.

       -6, --six
              The  default  action  of  this  utility is to issue MODE SENSE and MODE SELECT SCSI
              commands with 10 byte cdbs. When this option is given the 6 byte cdb  variants  are
              used.  RBC  and  old  SCSI  devices  may  need  this option. This utility outputs a
              suggestion to use this option if the SCSI status indicates that  the  10  byte  cdb
              variant is not supported.

       -t, --transport=TN
              Specifies  the  transport protocol where TN is either a number in the range 0 to 15
              (inclusive) or an abbreviation (e.g. "fcp" for the Fibre Channel Protocol). One way
              to list available transport protocols numbers and their associated abbreviations is
              to give an invalid transport protocol number such as '-t x';  another  way  is  '-e
              -l'.

       -M, --vendor=VN
              Specifies the vendor (i.e. manufacturer) where VN is either a number (0 or more) or
              an abbreviation (e.g. "sea" for Seagate disk vendor specific).   One  way  to  list
              available  vendor  numbers and their associated abbreviations is to give an invalid
              vendor number such as '-M x'; another way is '-e -l'.

       -v, --verbose
              increase the level of verbosity, (i.e. debug output). In some cases  more  decoding
              is done (e.g. fields within a standard INQUIRY response).

       -V, --version
              print the version string and then exit.

       -w, --wscan
              this  option  is  available  in Windows only. It lists storage device names and the
              corresponding volumes, if any. When used twice  it  adds  the  "bus  type"  of  the
              closest transport (e.g. a SATA disk in a USB connected enclosure has bus type Usb).
              When used three times a SCSI adapter scan is added. When used  four  times  only  a
              SCSI adapter scan is shown.  See examples below and the "Win32 port" section in the
              README file.

NOTES

       A mode page for which no abbreviation is known (e.g. a vendor specific mode page)  can  be
       listed in hexadecimal by using the option combination '--page=PG --hex'.

       Numbers  input to sdparm (e.g. in the command line arguments) are assumed to be in decimal
       unless there is a hexadecimal indicator. A hexadecimal indicator is either a leading  '0x'
       or  '0X'  (i.e.  the  C language convention) or a trailing 'h' or 'H' (i.e. the convention
       used at www.t10.org ). In the case of --page= either a string or number  is  expected,  so
       hex numbers like 'ch' (12) should be prefixed by a zero (e.g. '0ch').

       The  SPC-4  draft  (rev 2) says that devices that implement no distinction between current
       and saved pages can return an error (ILLEGAL REQUEST, invalid field in cdb) if the SP  bit
       (which  corresponds  to  the  --save option) is _not_ set. In such cases the --save option
       needs to be given.

       If the --save option is given but the existing mode page indicates (via its PS  bit)  that
       the  page  is  not  savable,  then  this  utility generates an error message. That message
       suggests to try again without the --save option.

       Since the device identification VPD page (acronym_name "di") potentially contains a lot of
       diverse  designators,  several  associated  acronyms  are  available. They are "di_lu" for
       designators  associated  with  the  addressed  logical  unit,  "di_port"  for  designators
       associated  with  the  target  port  (which  the  command arrived via) and "di_target" for
       designators associated with the target device. When "di" is used designators  are  grouped
       by lu, then port and then target device.  To see all designators decoded in the order that
       they appear in the VPD page use "di_asis".

       In the linux kernel 2.6 series any device node that understands a SCSI command  set  (e.g.
       SCSI  disks and CD/DVD drives) may be specified. More precisely the driver that "owns" the
       device node must support the SG_IO ioctl. In the lk 2.4  series  only  SCSI  generic  (sg)
       device nodes support the SG_IO ioctl. However in the lk 2.4 series other SCSI device nodes
       are mapped within this utility to their corresponding sg device nodes. So if  there  is  a
       SCSI  disk  at  /dev/sda  then  'sdparm  /dev/sda' will work in both the lk 2.6 and lk 2.4
       series. However if there is an ATAPI cd/dvd drive at /dev/hdc then 'sdparm /dev/hdc'  will
       only work in the lk 2.6 series.

       In  the  Linux  2.6  series, especially with ATA disks, using sdparm to stop (spin down) a
       disk may not be sufficient and other mechanisms will start the disk again some time later.
       The   user   might   additionally  mark  the  disk  as  "offline"  with  'echo  offline  >
       /sys/block/sda/device/state' where sda is the block name of the disk. To restart the  disk
       "offline" can be replaced with "running".

PARAMETERS

       In their simplest form the --clear=, --get= and --set= options (or their short forms) take
       an acronym_name such as "WCE". In the case of '--get=WCE' the value  of  "Writeback  Cache
       Enable" in the caching mode page will be fetched. In the case of '--set=WCE' that bit will
       be set (to one). In the case of '--clear=WCE' that bit will be cleared (to zero). When  an
       acronym_name is given then the mode page is imputed from that acronym_name (e.g. WCE is in
       the caching mode page).

       Instead of an acronym_name a field within a mode page can be described numerically with  a
       <start_byte>:<start_bit>:<num_bits>  tuple.  These  are the <start_byte> (origin 0) within
       the mode page, a <start_bit> (0 to 7 inclusive) and <num_bits> (1 to  64  inclusive).  For
       example,  the  low level representation of the RCD bit (the "Read Cache Disable bit in the
       caching mode page) is "2:0:1". The <start_byte> can  optionally  be  given  in  hex  (e.g.
       '--set=0x2:0:1'  or  '--set=2h:0:1').  With  this  form  the --page= option is required to
       establish which mode page is to be used.

       Either form can optionally be followed by "=<val>". By default <val> is decimal but can be
       given  in  hex  in  the  normal fashion. Here are some examples: '--set=2h:0:1=1h' and '-s
       MRIE=0x3'. When the acronym_name or numeric  form  following  --clear=  is  not  given  an
       explicit  '=<val>'  then the value defaults to zero. When the acronym_name or numeric form
       following --set= is not given an explicit '=<val>' then the value defaults to  "all  ones"
       (i.e.  as  many as <num_bits> permits). For example '--clear=WCE' and '--clear=WCE=0' have
       the same meaning: clear Writeback Cache Enable or, put more simply: turn off the writeback
       cache.

       Multiple  fields within the same mode page can be changed by giving a comma separated list
       of acronym_names and/or the numerical form. For example: '--set=TEST,MRIE=6'.

       Some mode page have multiple descriptors. They typically have a fixed  header  section  at
       the start of the mode page that includes a field containing the number of descriptors that
       follow. Following the header is a variable number of descriptors. An example  is  the  SAS
       Phy  Control and Discover mode page. An acronym_name may include a trailing '.<num>' where
       "<num>" is a descriptor number (origin 0). For example '-t sas -g PHID.0' and '-t  sas  -g
       PHID'  will  yield  the phy identifier of the first descriptor of the above mode page; '-t
       sas -g PHID.1' will yield the phy identifier of the second descriptor.

ENUMERATE

       The --enumerate option essentially dumps out static information held by  this  utility.  A
       list of --enumerate variants and their actions follows. For brevity subsequent examples of
       options are shown in their shorter form.

           --enumerate          list generic mode page information
           -e --all             list generic mode page contents
                                (i.e. parameters)
           -e --page=rw         list contents of read write error
                                recovery mode page
           -e --inquiry         list VPD pages this utility can decode
           -e --long            list generic mode pages, transport
                                protocols, mode pages for each
                                supported transport protocol and
                                supported commands
           -e -l --all          additionally list the contents of
                                each mode page
           -e --transport=fcp   list mode pages for the fcp
                                transport protocol
           -e -t fcp --all      additionally list the contents of
                                each mode page
           -e --vendor=sea      list vendor specific mode pages for
                                "sea" (Seagate)
           -e -M sea --all      additionally list the contents of vendor
                                specific mode pages for "sea" (Seagate)
           -e -p pcd -l         list contents of SAS phy control and
                                discovery mode page plus (due to "-l")
                                some descfriptor format information

       When known mode pages are listed (via the --enumerate  option) each line starts with a two
       or  three  letter  abbreviation.  This  is followed by the page number (in hex prefixed by
       "0x") optionally followed by a comma and the subpage number. Finally the descriptive  name
       of the mode page (e.g. as found in SPC-4) is output.

       When known parameters (fields) of a mode page are listed, each line starts with an acronym
       (indented a few spaces). This will match (or be an acronym for) the description  for  that
       field  found  in  the  (draft)  standards.  Next  are  three numbers, separated by colons,
       surrounded by brackets. These are the start  byte  (in  hex,  prefixed  by  "0x")  of  the
       beginning  of the field within the mode page; the starting bit (0 through 7 inclusive) and
       then the number of bits. The descriptive name of the parameter (field) is then  given.  If
       appropriate  the  descriptive  name  includes  units  (e.g.  "(ms)"  means  the  units are
       milliseconds). Adding the '-ll' option will list information about possible  field  values
       for selected mode page parameters.

       Mode  parameters  for  which  the  num_bits  is  greater  than 1 can be viewed as unsigned
       integers. Often 16 and 32 bit fields are set to 0xffff and  0xffffffff  respectively  (all
       ones)  which  usually has a special meaning (see drafts). This utility outputs such values
       as "-1" to save space (rather than their unsigned integer equivalents). "-1" can  also  be
       given  as  the  value to a mode page field acronym (e.g. '--set=INTT=-1' sets the interval
       timer field in the Informational Exceptions control mode page to 0xffffffff).

TRANSPORTS

       SCSI transport protocols are a relatively specialized area that can be safely  ignored  by
       the majority of users.

       Some  transport  protocols  have  protocol  specific  mode  pages.  These  are usually the
       disconnect-reconnect (0x2), the protocol specific logical unit  (0x18)  and  the  protocol
       specific  port (0x19) mode pages. In some cases the latter mode page has several subpages.
       The most common transport protocol abbreviations likely to be used are  "fcp",  "spi"  and
       "sas".

       Many  of  the  field names are re-used in the same position so the acronym_name namespaces
       have been divided between generic mode pages (i.e. when the --transport= option  is  _not_
       given)  and  a  namespace  for  each  transport  protocol. A LUPID field from the protocol
       specific logical unit (0x18) mode page and the PPID  field  from  protocol  specific  port
       (0x19)  mode  page  are  included  in  the  generic modes pages; this is so the respective
       (transport) protocol identifiers can be seen. In most cases the user will  know  what  the
       "port"  transport  is (i.e. the same transport as the HBA in the computer) but the logical
       unit's transport could be different.

VENDORS

       SCSI leaves a lot of space for vendor specific information. Often  this  is  described  in
       product manuals. The --vendor=VN (or -M=VN) option allows known vendor specific mode pages
       to be examined and/or modified by acronym.

       In this utility the syntax and semantics of vendor specific mode pages is very similar  to
       those of transport protocol specific mode pages. Both cannot be specified together. Vendor
       specific modes pages can still be accessed  numerically  (as  shown  at  the  end  of  the
       EXAMPLES section).

COMMANDS

       The  command  option sends a SCSI command to the DEVICE. If the command fails then this is
       reflected in the non-zero exit status.  To obtain more information about the error use the
       -v option.

       capacity
              sends  a  READ  CAPACITY  command (valid for disks and cd/dvd media). If successful
              yields "blocks: " [the number of blocks], "block_length: " [typically either 512 or
              2048] and "capacity_mib: " [capacity in MibiBytes (1048576 byte units)].

       eject  stops  the medium and ejects it from the device.  Note that ejection (by command or
              button) may be prevented in which case  the  'unlock'  command  may  be  useful  in
              extreme  cases.   Typically only appropriate for cd/dvd drives and disk drives with
              removable media. Objects if sent to another peripheral device type  (but  objection
              can be overridden with '-f' option).

       load   loads  the  medium  and  and starts it (i.e. spins it up).  See 'eject' command for
              supported device types.

       profile
              lists the various formats that a CD/DVD/HD-DVD/BD drive supports. These are  called
              "profiles"  in the MMC standard. The profiles are listed one per line.  If media is
              in the drive then the profile that matches the media (if any) has  an  "*"  to  the
              right of the line.

       ready  sends the "Test Unit Ready" SCSI command to the DEVICE. No error is reported if the
              device will respond to data requests (e.g. READ) in  a  reasonable  timescale.  For
              example,  if  a disk is stopped then it will report "not ready". All devices should
              respond to this command.

       sense  sends a REQUEST SENSE command. It reports a hardware threshold exceeded, warning or
              low  power condition if flagged. If a progress indication is present (e.g. during a
              format) then it will be output as a percentage. Yields a process status of 0 if the
              command  succeeds  and the sense key is 0; else yields 1. The --quiet option can be
              used to lessen output, and --hex to output sense data in hex.

       speed=SPEED
              permits the speed of a CD, DVD, HD_DVD or BD disc in a drive to be set (or at least
              influenced).  It has this format: --command=speed=SPEED where SPEED is in kilobytes
              per second. In this case a kilobyte is 1000 bytes. The "times one" speed for  a  CD
              is  176.4  kB/s, for a DVD is 1350 kB/s and for both HD-DVD and BD it is 4500 kB/s.
              If SPEED is zero then the drive is set to the speed that it considers gives optimal
              performance.   This  command sends a SET STREAMING multi-media command (MMC) to the
              drive.  The EXACT bit is  clear  so  the  drive  will  round  the  given  SPEED  as
              necessary.   The  command  is  designed  to control read speed; setting write speed
              should be left to "burning" programs.

       start  starts the medium (i.e. spins it up). Harmless if medium has already been  started.
              See  'eject'  command  for  supported device types. If the DEVICE is an ATA disk in
              Linux the '--readonly' option may be required.

       stop   stops the medium (i.e. spins it down). Harmless if medium has already been stopped.
              See  'eject'  command  for  supported device types. If the DEVICE is an ATA disk in
              Linux the '--readonly' option may be required. See the NOTES section above.

       sync   sends a SYNCHRONIZE CACHE command. The device should flush any  data  held  in  its
              (volatile) buffers to the media.

       unlock tells  a  device  to  allow  medium removal. It uses the SCSI "prevent allow medium
              removal" command. This is  desperation  stuff,  possibly  overriding  a  prevention
              applied  by  the OS on a mounted file system. The "eject" utility (from the "eject"
              package) is more  graceful  and  should  be  tried  first.  This  command  is  only
              appropriate for devices with removable media.

       For  loading  and  ejecting tapes the mt utility should be used (i.e. not these commands).
       The 'ready' command is valid for tape devices.

EXAMPLES

       To list the common (generic) mode parameters of a disk:

          sdparm /dev/sda

       To list the designators within the device identification VPD page of a disk:

          sdparm --inquiry /dev/sda

       To see all parameters for the caching mode page:

          sdparm --page=ca /dev/sda

       To see all parameters for the caching mode page with parameter descriptions to the right:

          sdparm --page=ca --long /dev/sda

       To get the WCE values (current changeable default and saved) in hex:

          sdparm -g WCE -H /dev/sda
       0x01 0x00 0x01 0x01

       To get the WCE current value in hex:

          sdparm -g WCE=1 -H /dev/sda
       0x01

       To set the "Writeback Cache Enable" bit in the current values page:

          sdparm --set=WCE /dev/sda

       To set the "Writeback Cache Enable" bit in the current and saved values page:

          sdparm --set=WCE --save /dev/sda

       To set the "Writeback Cache Enable" and clear "Read Cache Disable":

          sdparm --set=WCE --clear=RCD --save /dev/sda

       The previous example can also by written as:

          sdparm -s WCE=1,RCD=0 -S /dev/sda

       To re-establish the manufacturer's defaults in the current and saved values of the caching
       mode page:

          sdparm --page=ca --defaults --save /dev/sda

       If  an ATAPI cd/dvd drive is at /dev/hdc then its common (mode) parameters could be listed
       in the lk 2.6 series with:

          sdparm /dev/hdc

       If there is a DVD in the drive at /dev/hdc then it could be ejected in the lk  2.6  series
       with:

          sdparm --command=eject /dev/hdc

       If the ejection is being prevented by software then that can be overridden with:

          sdparm --command=unlock /dev/hdc

       One  disk  vendor  has a "Performance Mode" bit (PM) in the vendor specific unit attention
       mode page [0x0,0x0]. PM=0 is server mode (the default) while PM=1 is desktop mode. Desktop
       mode can be set (both current and saved values) with:

          sdparm --page=0 --set=2:7:1=1 --save /dev/sda

       The  resultant  change can be viewed in hex with the --hex option as there are no acronyms
       for vendor extensions yet. The PM bit is now covered by vendor specific mode pages and the
       above can also be accomplished with:

          sdparm --vendor=sea --set=PM --save /dev/sda

       What  follows  are  some  examples from Windows using the '--wscan' option. The idea is to
       list the storage device names on the system that might be invoked by other uses of sdparm.

         # sdparm --wscan
       PD0     [C]     FUJITSU   MHY2160BH         0000
       PD1     [DF]    WD        2500BEV External  1.05  WD-WXE90
       CDROM0  [E]     MATSHITA DVD/CDRW UJDA775  CB03

       So 'sdparm -a CDROM0' and 'sdparm -a E' will show all the (known) mode page fields for the
       Matshita  DVD/CD drive. By using the '--wsacan' option twice, the bus type (as seen by the
       OS) is added to the output:

         # sdparm -ww
       PD0     [C]     <Ata  >  FUJITSU   MHY2160BH         0000
       PD1     [DF]    <Usb  >  WD        2500BEV External  1.05  WD-WXE90
       CDROM0  [E]     <Atapi>  MATSHITA DVD/CDRW UJDA775  CB03

       And the pattern continues to add a SCSI adapter scan. This may  be  useful  if  there  are
       specialized  storage related devices (e.g. a SES device in an enclosure) but does add much
       extra information in this case.

         # sdparm -www
       PD0     [C]     <Ata  >  FUJITSU   MHY2160BH         0000
       PD1     [DF]    <Usb  >  WD        2500BEV External  1.05  WD-WXE90
       CDROM0  [E]     <Atapi>  MATSHITA DVD/CDRW UJDA775  CB03

       SCSI0:0,0,0   claimed=1 pdt=0h  FUJITSU   MHY2160BH         0000
       SCSI1:0,0,0   claimed=1 pdt=5h  MATSHITA  DVD/CDRW UJDA775  CB03

EXIT STATUS

       To aid scripts that call sdparm, the exit status is set to indicate success (0) or failure
       (1  or  more). Note that some of the lower values correspond to the SCSI sense key values.
       The exit status values are:

       0      success

       1      syntax error. Either illegal command line options, options with bad arguments or  a
              combination of options that is not permitted.

       2      the DEVICE reports that it is not ready for the operation requested. The device may
              be in the process of becoming ready (e.g.  spinning up but not  at  speed)  so  the
              utility may work after a wait.

       3      the  DEVICE  reports  a medium or hardware error (or a blank check). For example an
              attempt to read a corrupted block on a disk will yield this value.

       5      the DEVICE reports an "illegal request" with an additional sense  code  other  than
              "invalid  operation  code".  This  is  often  a  supported command with a field set
              requesting an unsupported capability. For commands that require a "service  action"
              field this value can indicate that the command is not supported.

       6      the  DEVICE  reports  a  "unit  attention"  condition.  This usually indicates that
              something unrelated to the requested command has occurred  (e.g.  a  device  reset)
              potentially before the current SCSI command was sent. The requested command has not
              been executed by the device. Note that unit attention conditions are  usually  only
              reported once by a device.

       9      the  DEVICE  reports  an  illegal request with an additional sense code of "invalid
              operation code" which means that it doesn't support the requested command.

       11     the DEVICE reports an aborted command.  In  some  cases  aborted  commands  can  be
              retried immediately (e.g. if the transport aborted the command due to congestion).

       15     the  utility is unable to open, close or use the given DEVICE.  The given file name
              could be incorrect or there may be permission problems. Adding the  -v  option  may
              give more information.

       20     the  DEVICE reports it has a check condition but "no sense".  Some polling commands
              (e.g. REQUEST SENSE) can react this way.  It is unlikely that this value will occur
              as an exit status.

       21     the  DEVICE reports a "recovered error". The requested command was successful. Most
              likely a utility will report a recovered error to  stderr  and  continue,  probably
              leaving the utility with an exit status of 0 .

       33     the command sent to DEVICE has timed out. This occurs in Linux only; in other ports
              a command timeout will appear as a transport (or OS) error.

       97     the response to a SCSI command failed sanity checks.

       98     the DEVICE reports it has a check condition but the error doesn't fit into  any  of
              the above categories.

       99     any errors that can't be categorized into values 1 to 98 may yield this value. This
              includes transport and operating system errors after the command has been  sent  to
              the device.

       Most  of the error conditions reported above will be repeatable (an example of one that is
       not is "unit attention") so the utility can be run again with the -v option  (or  several)
       to obtain more information.

AUTHORS

       Written by Douglas Gilbert.

REPORTING BUGS

       Report bugs to <dgilbert at interlog dot com>.

COPYRIGHT

       Copyright © 2005-2010 Douglas Gilbert
       This  software  is distributed under a FreeBSD license. There is NO warranty; not even for
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

WEB SITE

       There is a web page discussing this package at http://sg.danny.cz/sg/sdparm.html .

SEE ALSO

       hdparm(hdparm), sg_modes, sg_wr_mode, sginfo, sg_inq, sg_vpd, sg_scan(all  in  sg3_utils),
       smartmontools(smartmontools.sourceforge.net), mt, eject(eject),