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Updated: Thursday, June 13, 2019
 
 

sg_reassign (8)

Name

sg_reassign - send SCSI REASSIGN BLOCKS command

Synopsis

sg_reassign   [--address=A,A...]   [--dummy]   [--eight=0|1]  [--grown]
[--help] [--longlist=0|1] [--primary] [--verbose] [--version] DEVICE

Description

SG_REASSIGN(8)                     SG3_UTILS                    SG_REASSIGN(8)



NAME
       sg_reassign - send SCSI REASSIGN BLOCKS command

SYNOPSIS
       sg_reassign   [--address=A,A...]   [--dummy]   [--eight=0|1]  [--grown]
       [--help] [--longlist=0|1] [--primary] [--verbose] [--version] DEVICE

DESCRIPTION
       Send a SCSI REASSIGN BLOCKS command to DEVICE. Alternatively this util-
       ity  can  find  the  number of element in a "grown" or "primary" defect
       list with a SCSI READ DEFECT DATA (10) command. These SCSI commands are
       defined  in  SBC-2  for  direct  access devices (e.g. a disk). Reassign
       blocks is designed to change the physical location of a  logical  block
       that  is  known  or  suspected  to  be defective to another area on the
       media. Disks are typically formatted with blocks held  in  reserve  for
       this situation.

       If  neither  the  --grown  nor --primary option is supplied then one or
       more addresses need to  be  given.  If  the  address  (or  all  of  the
       addresses)  fit  into  4  bytes  and  '--eight=1' is not given then the
       parameter block passed to DEVICE is made up of  4  byte  logical  block
       addresses.  If any of the addresses need more than 4 bytes to represent
       (i.e. >= 2**32) or '--eight=1' is given then the parameter block passed
       to DEVICE is made up of 8 byte logical block addresses.

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

       -a, --address=A,A...
              where A,A... is a string of comma separated numbers. Each number
              is interpreted as decimal unless prefixed by '0x' or '0X' (or it
              has  a trailing 'h' or 'H'). If multiple logical block addresses
              are given they must be separated by a comma or a (single) space.
              A  string that contains any space separators needs to be quoted.
              At least one address must be given.

       -a, --address=-
              reads one or more logical block addresses from stdin. These  may
              be  comma, space, tab or linefeed (newline) separated. If a line
              contains "#" then the remaining  characters  on  that  line  are
              ignored.  Otherwise  each  non  separator sequence of characters
              should resolve to a decimal number unless prefixed  by  '0x'  or
              '0X'  (or  has  a  trailing  'h').  At least one address must be
              given. Lines should not be longer than 1023 bytes.

       -d, --dummy
              prepare for but do not execute the SCSI REASSIGN BLOCKS command.
              Since  the  REASSIGN BLOCKS command is essentially irreversible,
              paranoid users may wish to check the invocation of this  utility
              before reassigning defective blocks on a disk. Useful with '-vv'
              for those who wish to view the parameter block that will  accom-
              pany the command.

       -e, --eight=0 | 1
              when  value  is 1 then it sets the 'LONGLBA' flag in the command
              indicating that the addresses in the associated parameter  block
              are  8  byte  quantities.   When  value  is 0 then it clears the
              'LONGLBA' flag in the command indicating that the  addresses  in
              the  associated  parameter block are 4 byte quantities.  If this
              option is not given then 4 byte quantities  are  assumed  unless
              one of the address is too large.

       -g, --grown
              use the SCSI READ DEFECT DATA (10) command to determine the num-
              ber of elements in the "grown defect list". When this option  is
              given  there  is no reassignment of blocks (i.e. this utility is
              passive). When this option is given then the  --address=  option
              is  not permitted. See the discussion below concerning the rela-
              tionship between reassigned blocks and the  grown  defect  list.
              This list is sometimes referred to as the GLIST.

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

       -l, --longlist=0 | 1
              sets the REASSIGN BLOCKS cdb field of the same name to the given
              value.  Only 1000 addresses are permitted so there should be  no
              need  to  specify a value of 1. The short list variant restricts
              the parameter block length to 2 ** 16 bytes (i.e. about 16000  4
              byte  addresses  or  8000 8 byte addresses). Added for complete-
              ness.

       -p, --primary
              use the SCSI READ DEFECT DATA (10) command to determine the num-
              ber  of  elements  in  the "primary defect list" which is estab-
              lished during the manufacturing process.  When  this  option  is
              given  there  is no reassignment of blocks (i.e. this utility is
              passive). When this option is given then the  --address=  option
              is  not  permitted.  This  list  is sometimes referred to as the
              PLIST.

       -v, --verbose
              increase the level of verbosity, (i.e. debug output).

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


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+--------------------------+
       |ATTRIBUTE TYPE |     ATTRIBUTE VALUE      |
       +---------------+--------------------------+
       |Availability   | system/storage/sg3_utils |
       +---------------+--------------------------+
       |Stability      | Pass-through uncommitted |
       +---------------+--------------------------+
NOTES
       Note that if the ARRE field (for reads)  and/or  the  AWRE  field  (for
       writes)  are  set  in  the  "Read  Write Error Recovery" mode page then
       recoverable read and/or write errors cause  automatic  reassignment  of
       the defective block. The PER bit in the same mode page controls whether
       a RECOVERED ERROR sense key  is  reported  on  not  (PER=1  implies  do
       report).  Irrespective  of  the  ARRE,  AWRE or PER field settings, the
       error counter log pages reflect any errors  (recovered  or  otherwise).
       Whenever  a  block  is  reassigned, a new entry is added in the "grown"
       defect list. Apart from doing selftests (see sg_senddiag  or  smartmon-
       tools)  regularly, monitoring the grown defect list of a disk is a rea-
       sonable metric of its health. If the grown list starts growing  quickly
       that  is  an  ominous sign. The best grown defect lists are empty ones.
       The number of elements in the grown defect list can be viewed with  the
       --grown  option.  The  contents  of the grown defect list can be viewed
       with the 'sginfo -G' utility.

       If an unrecoverable error is detected at a logical block  address  then
       REASSIGN  BLOCKS  is  needed  to  reassign  the block. Also if the ARRE
       and/or AWRE fields are clear and a recoverable error is  detected  then
       the logical block in question may be reassigned with this utility (oth-
       erwise the error counter log pages will continually be incremented  for
       each recovered access).

       The  number  of  blocks  held  in  reserve for the purposes of REASSIGN
       BLOCKS is vendor specific and may well be limited to  the  zone  within
       the media where the original (defective) block lay. When this number is
       exhausted subsequent invocations of this utility may result in a  sense
       key of hardware error and an additional sense of 'No defect spare loca-
       tion available'. The next step would be to reformat the disk (or get  a
       replacement).

       The  SBC-2  draft  standard  (revision  16)  notes  that  when multiple
       addresses are given to the SCSI REASSIGN BLOCKS command  and  there  is
       some  failure at one of the later addresses then all addresses prior to
       that have already be reassigned. Care should be taken in such  a  case.
       Re-executing the command with the same addresses will cause the earlier
       addresses to be reassigned again. At some stage the disk will  run  out
       of  reserved  locations.   So  unless  a  large number of addresses are
       involved it may be safer to reassign them one address at a time.

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

AUTHORS
       Written by Douglas Gilbert.

REPORTING BUGS
       Report bugs to <dgilbert at interlog dot com>.

COPYRIGHT
       Copyright (C) 2005-2014 Douglas Gilbert
       This  software is distributed under a FreeBSD license. There is NO war-
       ranty; not even for MERCHANTABILITY or FITNESS FOR  A  PARTICULAR  PUR-
       POSE.

SEE ALSO
       sg_format,sginfo,sg_senddiag(all  in sg3_utils), sdparm(sdparm), smart-
       montools(internet, sourceforge)


       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source was downloaded from  http://sg.danny.cz/sg/p/sg3_utils-1.42.tgz

       Further information about this software can be found on the open source
       community website at http://sg.danny.cz/sg/sg3_utils.html.



sg3_utils-1.38                   January 2014                   SG_REASSIGN(8)