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.TH SG_READ_LONG "8" "August 2004" "sg3_utils-1.08" SG3_UTILS
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.TH SG_READ_LONG "8" "June 2006" "sg3_utils-1.21" SG3_UTILS
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sg_read_long \- send the scsi command read long
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sg_read_long \- calls a READ LONG command on a SCSI device
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[\fI--correct\fR] [\fI--help\fR] [\fI--lba=<num>\fR] [\fI--out=<name>\fR]
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[\fI--verbose\fR] [\fI--version\fR] [\fI--xfer_len=<num>\fR]
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[\fI--16\fR] [\fI--correct\fR] [\fI--help\fR] [\fI--lba=<num>\fR]
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[\fI--out=<name>\fR] [\fI--verbose\fR] [\fI--version\fR]
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[\fI--xfer_len=<num>\fR] \fI<scsi_device>\fR
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.\" Add any additional description here
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Send READ LONG command to a Linux SCSI device. The read
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buffer is output in hex and ASCII to stdout or placed in a file..
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buffer is output in hex and ASCII to stdout or placed in a file.
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Note that the data returned includes the logical block data (typically
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512 bytes for a disk) plus ECC information (whose format is proprietary)
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plus optionally other proprietary data.
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attempts a READ LONG(16) SCSI command. The default action is to attempt
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a READ LONG(10) SCSI command. The READ LONG(10) command has a 32 bit
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field for the lba while READ LONG(16) has a 64 bit field.
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sets the 'CORRCT' bit in the READ LONG SCSI command. When set the data is
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output the usage message then exit.
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--lba=<num> | -l <num>
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the logical block address of the sector to read. Defaults to lba 0.
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the logical block address of the sector to read. Assumed to be in
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decimal unless prefixed with '0x'. Defaults to lba 0. Only 32 bit
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lbas currently supported.
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--out=<name> | -o <name>
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instead of outputting ASCII hex to stdout, try to send it to the file
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the transfer length in bytes (default to 520). If the given value (or the
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default) does not match the "long" block size of the device, the
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appropriate xfer_len value is derived from the error response and
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printed (to stderr). The idea is that the user will retry this utility
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with the correct transfer length.
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If a defective block is found and its contents, if any, has been
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retrieved then "sg_reassign" could be used to map out the defective
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block. Associated with such an action the number of elements in
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the "grown" defect list could be monitored (with "sg_reassign --grown")
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as the disk could be nearing the end of its useful lifetime.
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The lba and xfer_len numerical arguments may be followed by the following
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multiplicative suffixes:
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c C *1; b B *512; k *1,024; K *1,000; m *1,048,576; M *1,000,000;
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g *1,073,741,824; and G *1,000,000,000
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c C *1; w W *2; b B *512; k K KiB *1,024; KB *1,000; m M MiB *1,048,576;
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MB *1,000,000; g G GiB *1,073,741,824; and GB *1,000,000,000 . Also a suffix
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of the form "x<n>" multiplies the leading number by <n>.
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Alternatively numerical values can be given in hexadecimal preceded by
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either "0x" or "0X". When hex numbers are given multipliers cannot be
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either "0x" or "0X" (or with a trailing "h" or "H"). When hex numbers are
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given, multipliers cannot be used.
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As a data point, Fujitsu uses a 54 byte ECC (per block) which is capable
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of correcting up to a single burst error or 216 bits "on the
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fly". [Information obtained from MAV20xxrc product manual.]
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The exit status of sg_read_long is 0 when it is successful. Otherwise see
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the sg3_utils(8) man page.
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Written by Douglas Gilbert.
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.SH "REPORTING BUGS"
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Report bugs to <dgilbert at interlog dot com>.
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Copyright \(co 2004 Douglas Gilbert
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Copyright \(co 2004-2006 Douglas Gilbert
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This software is distributed under the GPL version 2. There is NO
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warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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.B sg_write_long, sg_dd
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.B sg_reassign, sg_write_long, sg_dd
added
removed
sg_read_long.8
