kernelconfig-config.html

FreeBSD操作系统的详细使用手册

</pre>

<p>This option, present only in FreeBSD&nbsp;5.X, enables kernel support for access
control lists. This relies on the use of extended attributes and <acronym
class="ACRONYM">UFS2</acronym>, and the feature is described in detail in <a
href="fs-acl.html">Section 14.13</a>. <acronym class="ACRONYM">ACL</acronym>s are enabled
by default and should not be disabled in the kernel if they have been used previously on
a file system, as this will remove the access control lists, changing the way files are
protected in unpredictable ways.</p>

<pre class="PROGRAMLISTING">
options          UFS_DIRHASH       # Improve performance on big directories
</pre>

<p>This option includes functionality to speed up disk operations on large directories,
at the expense of using additional memory. You would normally keep this for a large
server, or interactive workstation, and remove it if you are using FreeBSD on a smaller
system where memory is at a premium and disk access speed is less important, such as a
firewall.</p>

<pre class="PROGRAMLISTING">
options          SOFTUPDATES       # Enable FFS Soft Updates support
</pre>

<p>This option enables Soft Updates in the kernel, this will help speed up write access
on the disks. Even when this functionality is provided by the kernel, it must be turned
on for specific disks. Review the output from <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=mount&sektion=8"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">mount</span>(8)</span></a> to see if
Soft Updates is enabled for your system disks. If you do not see the <var
class="LITERAL">soft-updates</var> option then you will need to activate it using the <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=tunefs&sektion=8"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">tunefs</span>(8)</span></a> (for
existing file systems) or <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=newfs&sektion=8"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">newfs</span>(8)</span></a> (for new file
systems) commands.</p>

<pre class="PROGRAMLISTING">
options          MD_ROOT           # MD is a potential root device
</pre>

<p>This option enables support for a memory backed virtual disk used as a root
device.</p>

<pre class="PROGRAMLISTING">
options          NFSCLIENT         # Network Filesystem Client
options          NFSSERVER         # Network Filesystem Server
options          NFS_ROOT          # NFS usable as /, requires NFSCLIENT
</pre>

<p>The network file system. Unless you plan to mount partitions from a <span
class="TRADEMARK">UNIX</span>&reg; file server over TCP/IP, you can comment these
out.</p>

<pre class="PROGRAMLISTING">
options          MSDOSFS           # MSDOS Filesystem
</pre>

<p>The <span class="TRADEMARK">MS-DOS</span>&reg; file system. Unless you plan to mount a
DOS formatted hard drive partition at boot time, you can safely comment this out. It will
be automatically loaded the first time you mount a DOS partition, as described above.
Also, the excellent <a
href="http://www.FreeBSD.org/cgi/url.cgi?ports/emulators/mtools/pkg-descr"><tt
class="FILENAME">emulators/mtools</tt></a> software allows you to access DOS floppies
without having to mount and unmount them (and does not require <var
class="LITERAL">MSDOSFS</var> at all).</p>

<pre class="PROGRAMLISTING">
options          CD9660            # ISO 9660 Filesystem
</pre>

<p>The ISO 9660 file system for CDROMs. Comment it out if you do not have a CDROM drive
or only mount data CDs occasionally (since it will be dynamically loaded the first time
you mount a data CD). Audio CDs do not need this file system.</p>

<pre class="PROGRAMLISTING">
options          PROCFS            # Process filesystem
</pre>

<p>The process file system. This is a ``pretend'' file system mounted on <tt
class="FILENAME">/proc</tt> which allows programs like <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=ps&sektion=1"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">ps</span>(1)</span></a> to give you more
information on what processes are running. In FreeBSD 5.X and above, use of <var
class="LITERAL">PROCFS</var> is not required under most circumstances, as most debugging
and monitoring tools have been adapted to run without <var class="LITERAL">PROCFS</var>:
unlike in FreeBSD 4.X, new installations of FreeBSD 5.X will not mount the process file
system by default. In addition, 6.X-CURRENT kernels making use of <var
class="LITERAL">PROCFS</var> must now also include support for <var
class="LITERAL">PSEUDOFS</var>:</p>

<pre class="PROGRAMLISTING">
options          PSEUDOFS          # Pseudo-filesystem framework
</pre>

<p><var class="LITERAL">PSEUDOFS</var> is not available in FreeBSD 4.X.</p>

<pre class="PROGRAMLISTING">
options          GEOM_GPT          # GUID Partition Tables.
</pre>

<p>This option brings the ability to have a large number of partitions on a single
disk.</p>

<pre class="PROGRAMLISTING">
options          COMPAT_43         # Compatible with BSD 4.3 [KEEP THIS!]
</pre>

<p>Compatibility with 4.3BSD. Leave this in; some programs will act strangely if you
comment this out.</p>

<pre class="PROGRAMLISTING">
options          COMPAT_FREEBSD4   # Compatible with FreeBSD4
</pre>

<p>This option is required on FreeBSD&nbsp;5.X <span class="TRADEMARK">i386</span>&#8482;
and Alpha systems to support applications compiled on older versions of FreeBSD that use
older system call interfaces. It is recommended that this option be used on all <span
class="TRADEMARK">i386</span> and Alpha systems that may run older applications;
platforms that gained support only in 5.X, such as ia64 and <span
class="TRADEMARK">Sparc64</span>&reg;, do not require this option.</p>

<pre class="PROGRAMLISTING">
options          SCSI_DELAY=15000  # Delay (in ms) before probing SCSI
</pre>

<p>This causes the kernel to pause for 15 seconds before probing each SCSI device in your
system. If you only have IDE hard drives, you can ignore this, otherwise you will
probably want to lower this number, perhaps to 5 seconds, to speed up booting. Of course,
if you do this and FreeBSD has trouble recognizing your SCSI devices, you will have to
raise it again.</p>

<pre class="PROGRAMLISTING">
options          KTRACE            # ktrace(1) support
</pre>

<p>This enables kernel process tracing, which is useful in debugging.</p>

<pre class="PROGRAMLISTING">
options          SYSVSHM           # SYSV-style shared memory
</pre>

<p>This option provides for System&nbsp;V shared memory. The most common use of this is
the XSHM extension in X, which many graphics-intensive programs will automatically take
advantage of for extra speed. If you use X, you will definitely want to include this.</p>

<pre class="PROGRAMLISTING">
options          SYSVSEM           # SYSV-style semaphores
</pre>

<p>Support for System&nbsp;V semaphores. Less commonly used but only adds a few hundred
bytes to the kernel.</p>

<pre class="PROGRAMLISTING">
options          SYSVMSG           # SYSV-style message queues
</pre>

<p>Support for System&nbsp;V messages. Again, this option only adds a few hundred bytes
to the kernel.</p>

<div class="NOTE">
<blockquote class="NOTE">
<p><b>Note:</b> The <var class="OPTION">-p</var> option of the <a
href="http://www.FreeBSD.org/cgi/man.cgi?query=ipcs&sektion=1"><span
class="CITEREFENTRY"><span class="REFENTRYTITLE">ipcs</span>(1)</span></a> command will
list any processes using each of these System&nbsp;V facilities.</p>
</blockquote>
</div>

<pre class="PROGRAMLISTING">
options         _KPOSIX_PRIORITY_SCHEDULING # POSIX P1003_1B real-time extensions
</pre>

<p>Real-time extensions added in the 1993 <span class="TRADEMARK">POSIX</span>&reg;.
Certain applications in the ports collection use these (such as <b
class="APPLICATION"><span class="TRADEMARK">StarOffice</span>&#8482;</b>).</p>

<pre class="PROGRAMLISTING">
options          KBD_INSTALL_CDEV  # install a CDEV entry in /dev
</pre>

<p>This option is related to the keyboard. It installs a CDEV entry in <tt
class="FILENAME">/dev</tt>.</p>

<pre class="PROGRAMLISTING">
options          AHC_REG_PRETTY_PRINT     # Print register bitfields in debug
                                          # output.  Adds ~128k to driver.
options          AHD_REG_PRETTY_PRINT     # Print register bitfields in debug
                                          # output.  Adds ~215k to driver.
</pre>

<p>This helps debugging by printing easier register definitions for reading.</p>

<pre class="PROGRAMLISTING">
options          ADAPTIVE_GIANT    # Giant mutex is adaptive.
</pre>

<p>This option causes Giant to be included in the set of mutexes adaptively spun on.</p>

<pre class="PROGRAMLISTING">
# To make an SMP kernel, the next two are needed
options         SMP                # Symmetric MultiProcessor Kernel
device          apic               # I/O APIC
</pre>

<p>The above are both required for SMP support, and can also be safely enabled on
uniprocessor systems.</p>

<pre class="PROGRAMLISTING">
device          isa
</pre>

<p>All PCs supported by FreeBSD have one of these. Do not remove this, even if you have
no ISA slots. If you have an IBM PS/2 (Micro Channel Architecture) system, FreeBSD
provides only limited support at this time. For more information about the MCA support,
see <tt class="FILENAME">/usr/src/sys/i386/conf/NOTES</tt>.</p>

<pre class="PROGRAMLISTING">
device          eisa
</pre>

<p>Include this if you have an EISA motherboard. This enables auto-detection and
configuration support for all devices on the EISA bus.</p>

<pre class="PROGRAMLISTING">
device          pci
</pre>

<p>Include this if you have a PCI motherboard. This enables auto-detection of PCI cards
and gatewaying from the PCI to ISA bus.</p>

<pre class="PROGRAMLISTING">
device          agp
</pre>

<p>Include this if you have an AGP card in the system. This will enable support for AGP,
and AGP GART for boards which have these features.</p>

<pre class="PROGRAMLISTING">
# Floppy drives
device          fdc
</pre>

<p>This is the floppy drive controller.</p>

<pre class="PROGRAMLISTING">
# ATA and ATAPI devices
device          ata
</pre>

<p>This driver supports all ATA and ATAPI devices. You only need one <var
class="LITERAL">device ata</var> line for the kernel to detect all PCI ATA/ATAPI devices
on modern machines.</p>

<pre class="PROGRAMLISTING">
device          atadisk                 # ATA disk drives
</pre>

<p>This is needed along with <var class="LITERAL">device ata</var> for ATA disk
drives.</p>

<pre class="PROGRAMLISTING">
device          ataraid                 # ATA RAID drives
</pre>

<p>This is needed along with <var class="LITERAL">device ata</var> for ATA RAID
drives.</p>

<pre class="PROGRAMLISTING">
<a id="KERNELCONFIG-ATAPI" name="KERNELCONFIG-ATAPI"></a>
device          atapicd                 # ATAPI CDROM drives
</pre>

<p>This is needed along with <var class="LITERAL">device ata</var> for ATAPI CDROM
drives.</p>

<pre class="PROGRAMLISTING">
device          atapifd                 # ATAPI floppy drives
</pre>

<p>This is needed along with <var class="LITERAL">device ata</var> for ATAPI floppy
drives.</p>

<pre class="PROGRAMLISTING">
device          atapist                 # ATAPI tape drives
</pre>

<p>This is needed along with <var class="LITERAL">device ata</var> for ATAPI tape
drives.</p>

<pre class="PROGRAMLISTING">
options         ATA_STATIC_ID           # Static device numbering
</pre>

<p>This makes the controller number static; without this, the device numbers are
dynamically allocated.</p>

<pre class="PROGRAMLISTING">
# SCSI Controllers
device          ahb        # EISA AHA1742 family
device          ahc        # AHA2940 and onboard AIC7xxx devices
device          ahd        # AHA39320/29320 and onboard AIC79xx devices
device          amd        # AMD 53C974 (Teckram DC-390(T))
device          isp        # Qlogic family
device          mpt        # LSI-Logic MPT-Fusion
#device         ncr        # NCR/Symbios Logic
device          sym        # NCR/Symbios Logic (newer chipsets)