SG3UTILS                                           SGVERIFY(1M)



NAME
     sgverify - invoke SCSI VERIFY command(s) on a block device

SYNOPSIS
     sgverify  [--bpc=BPC]  [--count=COUNT]   [--dpo]   [--help]
     [--lba=LBA] [--verbose] [--version] [--vrprotect=VRP] DEVICE

DESCRIPTION
     Sends one or more SCSI VERIFY commands to DEVICE. It is  the
     10  byte VERIFY command defined for block devices (see SBC-2
     at http:/www.t10.org).  Verify starts at the logical  block
     address  given  by  the  --lba=LBA  option and continues for
     --count=COUNT blocks. No more than --bpc=BPC blocks are ver-
     ified by each VERIFY command so if necessary multiple VERIFY
     commands are sent. No news is good news (i.e. if  there  are
     no verify errors detected no messages are sent to stderr and
     the Unix return status is 0).

OPTIONS
     Arguments to long options are mandatory for short options as
     well.   The options are arranged in alphabetical order based
     on the long option name.

     -b, --bpc=BPC
          where BPC specifies the maximum number of  blocks  that
          will  be  verified by a single SCSI VERIFY command. The
          default value is 128 blocks which equates to 64 KB  for
          a  disk with 512 byte blocks. If BPC is less than COUNT
          then multiple SCSI VERIFY commands are sent to the dev-
          ice. For recent block devices (disks) this value may be
          constrained by the maximum transfer length field in the
          block limits VPD page.

     -c, --count=COUNT
          where COUNT specifies the number of blocks  to  verify.
          The  default  value is 1 . If COUNT is greater than BPC
          (or its default value of 128) then multiple SCSI VERIFY
          commands are sent to the device. The sgreadcap utility
          can be used to find the maximum number of blocks that a
          block device (e.g. a disk) has.

     -d, --dpo
          disable page out changes the cache  retention  priority
          of  blocks  read  on  the  device's cache to the lowest
          priority. This means that blocks read by other commands
          are more likely to remain in the device's cache.

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

     -l, --lba=LBA
          where LBA specifies the logical block  address  of  the



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SG3UTILS                                           SGVERIFY(1M)



          first  block  to  start  the  verify  operation. LBA is
          assumed to be decimal unless  prefixed  by  '0x'  or  a
          trailing  'h' (see below). The default value is 0 (i.e.
          the start of the device).

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

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

     -P, --vrprotect=VRP
          where VRP is the value in the vrprotect  field  in  the
          VERIFY  command cdb. It must be a value between 0 and 7
          inclusive. The default value is zero.

NOTES
     The BPC, COUNT and LBA arguments may be followed by  one  of
     these  multiplicative suffixes:  c C *1; w W *2; b B *512; k
     K KiB *1,024; KB *1,000; m M MiB *1,048,576; MB  *1,000,000;
     g G GiB *1,073,741,824; GB *1,000,000,000; t T TiB *(2**40);
     TB *(10**12); p P PiB *(2**50) and PB *(10**15). The "T" and
     "P"  based suffixes can only be used for COUNT and LBA. Also
     a suffix of the form "x" multiplies the leading number by
     .

     Alternatively numerical values can be given  in  hexadecimal
     preceded  by  either  "0x" or "0X" (or has a trailing "h" or
     "H"). When hex numbers  are  given,  multipliers  cannot  be
     used.

     The amount of error correction and  the  number  of  retries
     attempted  before  a  block is considered defective are con-
     trolled in part by the Verify Error Recovery mode  page.   A
     note  in the SBC-2 (draft) standard advises that to minimize
     the number of checks (and hence have  the  most  "sensitive"
     verify  check)  do  the following in that mode page. Set the
     ER bit to 0, the PER bit to 1, the DTE bit to  1,  the  DCR
     bit  to  1, the verify retry count to 0 and the verify error
     recovery timeout to 0. Mode pages can be modified  with  the
     sginfo utility.

EXIT STATUS
     The exit status of sgverify is 0  when  it  is  successful.
     Otherwise see the sg3utils(1M) man page.

AUTHORS
     Written by Douglas Gilbert.

REPORTING BUGS
     Report bugs to .




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SG3UTILS                                           SGVERIFY(1M)



COPYRIGHT
     Copyright O 2004-2007 Douglas Gilbert
     This software is distributed under a FreeBSD license.  There
     is  NO warranty; not even for MERCHANTABILITY or FITNES FOR
     A PARTICULAR PURPOSE.

SEE ALSO
     sginfo(sg3utils),                      sgmodes(sg3utils),
     sgreadcap(sg3utils), sginq(sg3utils)

ATRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:

     
       ATRIBUTE TYPE     ATRIBUTE VALUE
    
     Availability         SUNWsg3utilsu  
    
     Interface Stability  Committed      
    

NOTES
     Source for sg3utils is available on http:/opensolaris.org.































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