x4069.html

FreeBSD安装说明概述 FreeBSD 提供了一个以文字为主

<div class="INFORMALTABLE"><a id="AEN4197" name="AEN4197"></a>
<table border="0" frame="void" class="CALSTABLE">
<col width="1*" />
<col width="5*" />
<thead>
<tr>
<th>Partition</th>
<th>Convention</th>
</tr>
</thead>

<tbody>
<tr>
<td><var class="LITERAL">a</var></td>
<td>Normally contains the root filesystem</td>
</tr>

<tr>
<td><var class="LITERAL">b</var></td>
<td>Normally contains swap space</td>
</tr>

<tr>
<td><var class="LITERAL">c</var></td>
<td>Normally the same size as the enclosing slice. This allows utilities that need to
work on the entire slice (for example, a bad block scanner) to work on the <var
class="LITERAL">c</var> partition. You would not normally create a filesystem on this
partition.</td>
</tr>

<tr>
<td><var class="LITERAL">d</var></td>
<td>Partition <var class="LITERAL">d</var> used to have a special meaning associated with
it, although that is now gone. To this day, some tools may operate oddly if told to work
on partition <var class="LITERAL">d</var>, so <b class="APPLICATION">sysinstall</b> will
not normally create partition <var class="LITERAL">d</var>.</td>
</tr>
</tbody>
</table>
</div>

<p>Each partition-that-contains-a-filesystem is stored in what FreeBSD calls a <i
class="FIRSTTERM">slice</i>. Slice is FreeBSD's term for what were earlier called
partitions, and again, this is because of FreeBSD's <span class="TRADEMARK">UNIX</span>
background. Slices are numbered, starting at 1, through to 4.</p>

<p>Slice numbers follow the device name, prefixed with an <var class="LITERAL">s</var>,
starting at 1. So ``da0<span class="emphasis"><i class="EMPHASIS">s1</i></span>'' is the
first slice on the first SCSI drive. There can only be four physical slices on a disk,
but you can have logical slices inside physical slices of the appropriate type. These
extended slices are numbered starting at 5, so ``ad0<span class="emphasis"><i
class="EMPHASIS">s5</i></span>'' is the first extended slice on the first IDE disk. These
devices are used by file systems that expect to occupy a slice.</p>

<p>Slices, ``dangerously dedicated'' physical drives, and other drives contain <i
class="FIRSTTERM">partitions</i>, which are represented as letters from <var
class="LITERAL">a</var> to <var class="LITERAL">h</var>. This letter is appended to the
device name, so ``da0<span class="emphasis"><i class="EMPHASIS">a</i></span>'' is the a
partition on the first da drive, which is ``dangerously dedicated''. ``ad1s3<span
class="emphasis"><i class="EMPHASIS">e</i></span>'' is the fifth partition in the third
slice of the second IDE disk drive.</p>

<p>Finally, each disk on the system is identified. A disk name starts with a code that
indicates the type of disk, and then a number, indicating which disk it is. Unlike
slices, disk numbering starts at 0. Common codes that you will see are listed in <a
href="x4069.html#INSTALL-DEV-CODES">Table 3-1</a>.</p>

<p>When referring to a partition FreeBSD requires that you also name the slice and disk
that contains the partition, and when referring to a slice you should also refer to the
disk name. Do this by listing the disk name, <var class="LITERAL">s</var>, the slice
number, and then the partition letter. Examples are shown in <a
href="x4069.html#INSTALL-DISK-SLICE-PART">Example 3-1</a>.</p>

<p><a href="x4069.html#INSTALL-CONCEPT-DISK-MODEL">Example 3-2</a> shows a conceptual
model of the disk layout that should help make things clearer.</p>

<p>In order to install FreeBSD you must first configure the disk slices, then create
partitions within the slice you will use for FreeBSD, and then create a filesystem (or
swap space) in each partition, and decide where that filesystem will be mounted.</p>

<div class="TABLE"><a id="INSTALL-DEV-CODES" name="INSTALL-DEV-CODES"></a>
<p><b>Table 3-1. Disk Device Codes</b></p>

<table border="0" frame="void" class="CALSTABLE">
<col width="1*" />
<col width="5*" />
<thead>
<tr>
<th>Code</th>
<th>Meaning</th>
</tr>
</thead>

<tbody>
<tr>
<td><tt class="DEVICENAME">ad</tt></td>
<td>ATAPI (IDE) disk</td>
</tr>

<tr>
<td><tt class="DEVICENAME">da</tt></td>
<td>SCSI direct access disk</td>
</tr>

<tr>
<td><tt class="DEVICENAME">acd</tt></td>
<td>ATAPI (IDE) CDROM</td>
</tr>

<tr>
<td><tt class="DEVICENAME">cd</tt></td>
<td>SCSI CDROM</td>
</tr>

<tr>
<td><tt class="DEVICENAME">fd</tt></td>
<td>Floppy disk</td>
</tr>
</tbody>
</table>
</div>

<div class="EXAMPLE"><a id="INSTALL-DISK-SLICE-PART" name="INSTALL-DISK-SLICE-PART"></a>
<p><b>Example 3-1. Sample Disk, Slice, and Partition Names</b></p>

<div class="INFORMALTABLE"><a id="AEN4292" name="AEN4292"></a>
<table border="0" frame="void" class="CALSTABLE">
<col width="1*" />
<col width="5*" />
<thead>
<tr>
<th>Name</th>
<th>Meaning</th>
</tr>
</thead>

<tbody>
<tr>
<td><var class="LITERAL">ad0s1a</var></td>
<td>The first partition (<var class="LITERAL">a</var>) on the first slice (<var
class="LITERAL">s1</var>) on the first IDE disk (<var class="LITERAL">ad0</var>).</td>
</tr>

<tr>
<td><var class="LITERAL">da1s2e</var></td>
<td>The fifth partition (<var class="LITERAL">e</var>) on the second slice (<var
class="LITERAL">s2</var>) on the second SCSI disk (<var class="LITERAL">da1</var>).</td>
</tr>
</tbody>
</table>
</div>
</div>

<div class="EXAMPLE"><a id="INSTALL-CONCEPT-DISK-MODEL"
name="INSTALL-CONCEPT-DISK-MODEL"></a>
<p><b>Example 3-2. Conceptual Model of a Disk</b></p>

<p>This diagram shows FreeBSD's view of the first IDE disk attached to the system. Assume
that the disk is 4&nbsp;GB in size, and contains two 2&nbsp;GB slices (DOS partitions).
The first slice contains a DOS disk, <tt class="DEVICENAME">C:</tt>, and the second slice
contains a FreeBSD installation. This example FreeBSD installation has three partitions,
and a swap partition.</p>

<p>The three partitions will each hold a filesystem. Partition <var
class="LITERAL">a</var> will be used for the root filesystem, <var
class="LITERAL">e</var> for the <tt class="FILENAME">/var</tt> directory hierarchy, and
<var class="LITERAL">f</var> for the <tt class="FILENAME">/usr</tt> directory
hierarchy.</p>

<p><img src="install/disk-layout.png" /></p>
</div>
</div>

<div class="NAVFOOTER">
<hr align="LEFT" width="100%" />
<table summary="Footer navigation table" width="100%" border="0" cellpadding="0"
cellspacing="0">
<tr>
<td width="33%" align="left" valign="top"><a href="dirstructure.html"
accesskey="P">Prev</a></td>
<td width="34%" align="center" valign="top"><a href="index.html"
accesskey="H">Home</a></td>
<td width="33%" align="right" valign="top"><a href="mount-unmount.html"
accesskey="N">Next</a></td>
</tr>

<tr>
<td width="33%" align="left" valign="top">Directory Structure</td>
<td width="34%" align="center" valign="top"><a href="basics.html"
accesskey="U">Up</a></td>
<td width="33%" align="right" valign="top">Mounting and Unmounting File Systems</td>
</tr>
</table>
</div>
</body>
</html>