Provided by: sg3-utils_1.36-1ubuntu1_amd64 bug

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  utility  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.

       -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 accompany 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 number 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
              relationship 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 completeness.

       -p, --primary
              use the SCSI READ DEFECT DATA (10) command to determine the number of  elements  in
              the  "primary  defect  list" which is established 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.

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  smartmontools)
       regularly,  monitoring  the  grown  defect  list  of  a disk is a reasonable 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 (otherwise 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  location  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 © 2005-2012 Douglas Gilbert
       This  software  is distributed under a FreeBSD license. There is NO warranty; not even for
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO

       sg_format,sginfo,sg_senddiag(all in  sg3_utils),  sdparm(sdparm),  smartmontools(internet,
       sourceforge)