237 lines
4.5 KiB
HTML
237 lines
4.5 KiB
HTML
<HTML
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><HEAD
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><TITLE
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>Introduction</TITLE
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>The Linux SCSI Generic (sg) HOWTO</TH
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CLASS="CHAPTER"
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><H1
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><A
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NAME="INTRO">Chapter 1. Introduction</H1
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><P
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>This document outlines the Linux SCSI Generic (<SPAN
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CLASS="ABBREV"
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>sg</SPAN
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>) driver
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interface as found in the 2.4 series kernels. The driver's purpose is to
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allow SCSI commands to be sent directly to SCSI devices. The responses of
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those commands can then be obtained. This type of driver is sometimes termed
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as a "pass through".
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In the case of SCSI disks, the block subsystem which is normally used to
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mount and access a disk, is bypassed permitting low level operations such as
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formatting to be performed. Various specialized applications for writing
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CD-Rs and document scanning use the sg driver.</P
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><P
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>Many devices that use other physical buses (e.g. ATAPI cdroms, USB
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mass storage devices and IEEE 1394 sbp2 devices) utilize the SCSI command
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set. By using Linux pseudo SCSI device drivers which bridge between
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the native protocol stack and the SCSI subsystem, the upper level
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SCSI device drivers, including sg, can be used to control "non-SCSI"
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devices.</P
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><P
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>This is the third major version of the sg driver.
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A summary of the sg driver history is as follows:
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<P
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></P
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><UL
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><LI
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><P
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>sg version 1 (original) from 1992 to early 1999
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(lk 2.2.5) . A copy of the original HOWTO (in plain text) is at
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<A
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HREF="http://www.torque.net/sg/p/original/SCSI-Programming-HOWTO.txt"
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TARGET="_top"
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><TT
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CLASS="LITERAL"
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>www.torque.net/sg/p/original/SCSI-Programming-HOWTO.txt</TT
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></A
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></P
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></LI
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><LI
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><P
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>sg version 2 from lk 2.2.6 in the 2.2 series. Its
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documentation is available in abridged form
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[<A
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HREF="http://www.torque.net/sg/p/scsi-generic.txt"
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TARGET="_top"
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><TT
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CLASS="LITERAL"
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>www.torque.net/sg/p/scsi-generic.txt</TT
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></A
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>]
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and a longer form
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[<A
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HREF="http://www.torque.net/sg/p/scsi-generic_long.txt"
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TARGET="_top"
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><TT
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CLASS="LITERAL"
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>www.torque.net/sg/p/scsi-generic_long.txt</TT
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></A
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>].</P
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></LI
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><LI
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><P
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>sg version 3 in the linux kernel 2.4 series. </P
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></LI
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></UL
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>
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This document can be found at the Linux Documentation Project's site at
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<A
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HREF="http://www.linuxdoc.org/HOWTO/SCSI-Generic-HOWTO/"
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TARGET="_top"
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><TT
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CLASS="LITERAL"
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>www.linuxdoc.org/HOWTO/SCSI-Generic-HOWTO/</TT
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></A
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> .
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It is available in plain text and pdf renderings at that site.
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A (possibly later) version of this document can be found at
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<A
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HREF="http://www.torque.net/sg/p/sg_v3_ho.html"
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TARGET="_top"
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><TT
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CLASS="LITERAL"
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>www.torque.net/sg/p/sg_v3_ho.html</TT
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></A
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>.
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That is a single html page; drop the ".html" extension for multi-page
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html. There are also postscript, pdf and rtf renderings from the original
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SGML (docbook) file at the same location.</P
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><P
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>A more general description of the Linux SCSI subsystem of which sg is a
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part can be found in the
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<A
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HREF="http://www.linuxdoc.org/HOWTO/SCSI-2.4-HOWTO"
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TARGET="_top"
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>
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<TT
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CLASS="LITERAL"
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>SCSI-2.4-HOWTO</TT
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></A
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>.</P
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><P
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>This document was last modified on 3rd May 2002.</P
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>The Linux SCSI Generic (sg) HOWTO</TD
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><TD
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WIDTH="34%"
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> </TD
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ALIGN="right"
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VALIGN="top"
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>What the sg driver does</TD
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> |