SG_READ_LONG(8) 						     SG3_UTILS							   SG_READ_LONG(8)

NAME

       sg_read_long - send a SCSI READ LONG command

SYNOPSIS

       sg_read_long [--16] [--correct] [--help] [--lba=LBA] [--out=OF] [--pblock] [--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  option-
       ally other proprietary data.

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.

       -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.

       The LBA and BTL (transfer length) arguments may be followed by the following 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; and GB *1,000,000,000 . Also a suffix of the form "x<n>" mul-
       tiplies the leading number by <n>.

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

       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 (C) 2004-2007 Douglas Gilbert
       This software is distributed under the GPL version 2. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A  PARTICULAR  PUR-
       POSE.

SEE ALSO

       sg_reassign, sg_write_long, sg_dd

sg3_utils-1.23							   January 2007 						   SG_READ_LONG(8)