NAME

       sg_read_long - send a SCSI READ LONG command

SYNOPSIS

       sg_read_long  [--16]  [--correct]  [--help]  [--lba=LBA]  [--out=OF]  [--pblock] [--readonly] [--verbose]
       [--version] [--xfer_len=BTL] DEVICE

DESCRIPTION

       Send SCSI READ LONG command to DEVICE. The read buffer is output in hex and ASCII to stdout or placed  in
       a file. Note that the data returned includes the logical block data (typically 512 bytes for a disk) plus
       ECC  information  (whose  format  is  proprietary)  plus optionally other proprietary data. Note that the
       logical block data may be encoded or encrypted.

       In SBC-4 revision 7 the SCSI READ LONG (10 and 16 byte) commands were made obsolete. In the same revision
       all uses of SCSI WRITE LONG (10 and 16 byte) commands were made obsolete apart from the case in which the
       WR_UNCOR bit is set.

OPTIONS

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

       -S, --16
              uses a SCSI READ LONG(16) command. The default action is to use a SCSI READ LONG(10) command.  The
              READ LONG(10) command has a 32 bit field for the lba while READ LONG(16) has a 64 bit field.

       -c, --correct
              sets  the  'CORRCT'  bit  in the SCSI READ LONG command. When set the data is corrected by the ECC
              before being transferred back to this utility. The default is to leave the 'CORRCT' bit  clear  in
              which case the data is not corrected.

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

       -l, --lba=LBA
              where  LBA  is  the  logical  block address of the sector to read. Assumed to be in decimal unless
              prefixed with '0x' (or has a trailing 'h'). Defaults to lba 0. If the lba is larger than  can  fit
              in 32 bits then the --16 option should be used.

       -o, --out=OF
              instead  of  outputting  ASCII  hex  to stdout, send it in binary to the file called OF. If '-' is
              given for OF then the (binary) output is sent to stdout.  Note  that  all  informative  and  error
              output is sent to stderr.

       -p, --pblock
              sets  the  'PBLOCK' bit in the SCSI READ LONG command. When set the physical block (plus ECC data)
              containing the requested logical block address is read. The default is to leave the  'PBLOCK'  bit
              clear in which case the logical block (plus any ECC data) is read.

       -r, --readonly
              opens  the DEVICE read-only rather than read-write which is the default. The Linux sg driver needs
              read-write access for the SCSI READ LONG command but other access methods  may  require  read-only
              access.

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

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

       -x, --xfer_len=BTL
              where  BTL  is the byte transfer length (default to 520). If the given value (or the default) does
              not match the "long" block size of the device, the appropriate  BTL  is  deduced  from  the  error
              response  and  printed  (to  stderr).  The  idea is that the user will retry this utility with the
              correct transfer length.

NOTES

       If a defective block is found and its contents, if any, has been retrieved then  "sg_reassign"  could  be
       used to map out the defective block. Associated with such an action the number of elements in the "grown"
       defect  list  could be monitored (with "sg_reassign --grown") as the disk could be nearing the end of its
       useful lifetime.

       Various numeric arguments (e.g. LBA) may include multiplicative suffixes or be given in hexadecimal.  See
       the "NUMERIC ARGUMENTS" section in the sg3_utils(8) man page.

       As  a  data  point,  Fujitsu uses a 54 byte ECC (per block) which is capable of correcting up to a single
       burst error or 216 bits "on the fly". [Information obtained from MAV20xxrc product manual.]

EXIT STATUS

       The exit status of sg_read_long 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 © 2004-2016 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

       sg_reassign, sg_write_long, sg_dd

sg3_utils-1.42                                    November 2015                                  SG_READ_LONG(8)