203 lines
3.1 KiB
HTML
203 lines
3.1 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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><HEAD
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><TITLE
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>Disk driver (sd)</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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REL="HOME"
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TITLE="The Linux 2.4 SCSI subsystem HOWTO"
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HREF="index.html"><LINK
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REL="UP"
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TITLE="Upper level drivers"
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HREF="ulevel.html"><LINK
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REL="PREVIOUS"
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TITLE="Upper level drivers"
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HREF="ulevel.html"><LINK
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REL="NEXT"
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TITLE="CDROM driver (sr or scd)"
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HREF="sr.html"></HEAD
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><BODY
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CLASS="sect1"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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LINK="#0000FF"
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VLINK="#840084"
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ALINK="#0000FF"
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><DIV
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CLASS="NAVHEADER"
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><TABLE
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SUMMARY="Header navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>The Linux 2.4 SCSI subsystem HOWTO</TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="ulevel.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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>Chapter 9. Upper level drivers</TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="sr.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="sect1"
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><H1
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CLASS="sect1"
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><A
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NAME="sd"
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></A
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>9.1. Disk driver (sd)</H1
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><P
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> Two types of SCSI devices are accessible via the sd driver:
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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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>"direct access" devices which are usually magnetic disks.
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[SCSI peripheral device code is 0]</P
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></LI
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><LI
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><P
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>"Optical memory devices" which are often called MOD
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disks. [SCSI peripheral device code is 7]</P
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></LI
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></UL
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>
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The sd driver is a block device which means that it is closely associated
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with the block subsystem. It also supports the concept of partitions.
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[<B
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CLASS="command"
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>man sd</B
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> dates from 1992.]
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</P
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><P
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> The sd driver is capable of recognizing 128 disks when it is loaded
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at kernel boot time or later as a module. However, once it is loaded,
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it will only recognize a fixed number of additional disks. The number
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of additional disks that can be accommodated is set by the kernel
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configuration parameter CONFIG_SD_EXTRA_DEVS whose default value is 40.
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</P
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><DIV
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CLASS="sect2"
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><H2
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CLASS="sect2"
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><A
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NAME="sdbparams"
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></A
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>9.1.1. sd boot parameters</H2
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><P
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> None.
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</P
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></DIV
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><DIV
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CLASS="sect2"
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><H2
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CLASS="sect2"
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><A
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NAME="sdmparams"
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></A
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>9.1.2. sd module parameters</H2
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><P
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> The sd driver takes no parameters when loaded as a module. Note that
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its module name is <TT
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CLASS="filename"
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>sd_mod.o</TT
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>.
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</P
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></DIV
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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SUMMARY="Footer navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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><A
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HREF="ulevel.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="index.html"
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ACCESSKEY="H"
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>Home</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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><A
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HREF="sr.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>Upper level drivers</TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="ulevel.html"
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ACCESSKEY="U"
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>Up</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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>CDROM driver (sr or scd)</TD
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></TR
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></TABLE
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></DIV
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></BODY
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></HTML
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> |