SG_READ(8) SG3_UTILS SG_READ(8) (NAME) sg_read - SCSI READ (SYNOPSIS) sg_read [blk_sgio=0|1] [bpt=BPT] [bs=BS] [cdbsz=6|10|12|16] count=COUNT [dio=0|1] [dpo=0|1] [fua=0|1] if=IFILE [mmap=0|1] [no_dxfer=0|1] [odir=0|1] [skip=SKIP] [time=TI] [verbose=VERB] [--help] [--version] (DESCRIPTION) SCSI (sg) (lba) . ( ) () SCSI ( ) / SCSI . COUNT BPT COUNT . lba SKIP . COUNT IFILE sg 'blk_sgio=1' . 'bpt=0' . |COUNT| SCSI READ " " . " " SCSI READ " " ( ). " " SCSI READ SCSI . : LBA . . sg_dd ddpt . (OPTIONS) blk_sgio=0 | 1 ()read IFILE . 2.6 SCSI ioctl SG_IO . ioctl SG_IO SCSI READ IFILE . bpt=BPT BPT . COUNT BPT . BPT 128 . lba ( skip=SKIP 0). 'bpt=0' COUNT SCSI READ . bs=BS BS ( ) . SCSI IFILE ( 512 ). cdbsz=6 | 10 | 12 | 16 SCSI READ sg 'blk_sgio=1'. SCSI READ . count=COUNT COUNT . COUNT |COUNT| SCSI READ . . dio=0 | 1 0 / . 1 / / . IFILE sg . / /sys/module/sg/parameters/allow_dio 0 / . dpo=0 | 1 (DPO) SCSI READ . DPO (). fua=0 | 1 (FUA) SCSI READ . FUA (). if=IFILE IFILE. . IFILE (seekable) ( (COUNT > BPT) skip=SKIP ). (stdin) ( "-" IFILE ). mmap=0 | 1 0 / . 1 / (memory mapped IO) . dio mmap . IFILE sg . no_dxfer=0 | 1 DMA ( ). 0 . mmap dio ( ). . odir=0 | 1 IFILE O_DIRECT . 0 ( O_DIRECT). skip=SKIP SKIP ( bs) ( ) . time=TI TI 0 () . 1 . 2 . 3 . ( SCSI READ ()read) . verbose=VERB VERB stderr . . 1 . --help . --version . (NOTES) ( SKIP) . "NUMERIC ARGUMENTS" sg3_utils(8) . : SCSI DMA sg . "/ " (indirect IO) "dio" "/ " (direct IO) DMA . "/ " sg . "echo 1 > /sys/module/sg/parameters/allow_dio" . / 'mmap=1' . (SIGNALS) dd : SIGINT SIGQUIT SIGPIPE . SIGUSR1 . stderr . (EXAMPLES) /dev/sg0 () : sg_read if=/dev/sg0 bs=512 count=1MB mmap=1 time=2 . "128" 'bpt' " 0" 'skip' . ,, . 'time=2' . : time from second command to end was 4.50 secs, 113.70 MB/sec Average number of READ commands per second was 1735.27 1000000+0 records in, SCSI commands issued: 7813 (EXIT STATUS) sg_read 0 . sg3_utils(8) . (AUTHORS) Douglas Gilbert. (REPORTING BUGS) . (COPYRIGHT) (C) 2000-2019 Douglas Gilbert GPL . . (SEE ALSO) sg_dd sg3_utils ddpt . lmbench lmdd . raw(8), dd(1) sg3_utils-1.45 September 2019 SG_READ(8)