path: root/zh_CN.GB2312/books/handbook/geom/chapter.xml

<?xml version="1.0" encoding="gb2312"?>
<!--
     The FreeBSD Documentation Project
     The FreeBSD Simplified Chinese Project

     Original Revision: r38401
     $FreeBSD$
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<chapter id="GEOM">
  <chapterinfo>
    <authorgroup>
      <author>
	<firstname>Tom</firstname>
	<surname>Rhodes</surname>
	<contrib>Ô­×÷ </contrib>
      </author>
    </authorgroup>
  </chapterinfo>

  <title>GEOM£º Ä£¿é»¯´ÅÅ̱任¿ò¼Ü</title>

  <sect1 id="GEOM-synopsis">
    <title>¸ÅÊö</title>

    <indexterm>
      <primary>GEOM</primary>
    </indexterm>
    <indexterm>
      <primary>GEOM ´ÅÅÌ¿ò¼Ü</primary>
      <see>GEOM</see>
    </indexterm>

    <para>±¾Õ½«½éÉÜÒÔ &os; GEOM ¿ò¼ÜÀ´Ê¹ÓôÅÅÌ¡£
      Õâ°üÀ¨ÁËʹÓÃÕâÒ»¿ò¼ÜÀ´ÅäÖõÄÖ÷ÒªµÄ <acronym
      role="Redundant Array of Inexpensive Disks">RAID</acronym>
      ¿ØÖƹ¤¾ß¡£ ÕâÒ»Õ²»»áÉîÈëÌÖÂÛ GEOM
      ÈçºÎ´¦Àí»ò¿ØÖÆ I/O¡¢ ÆäϲãµÄ×Óϵͳ»ò´úÂë¡£
      Äú¿ÉÒÔ´Ó &man.geom.4; Áª»úÊֲἰÆäÖÚ¶à SEE ALSO ²Î¿¼ÎÄÏ×Öеõ½ÕâЩÐÅÏ¢¡£
      ÕâÒ»ÕÂÒ²²»ÊÇ¶Ô <acronym>RAID</acronym> ÅäÖõÄȨÍþ½éÉÜ£¬
      ËüÖ»½éÉÜÓÉ Ö§³ÖGEOM µÄ <acronym>RAID</acronym>
      ¼¶±ð¡£</para>

    <para>¶ÁÍêÕâÕ£¬ Äú½«Á˽⣺</para>

    <itemizedlist>
      <listitem>
	<para>ͨ¹ý GEOM Ö§³ÖµÄ <acronym>RAID</acronym> ÀàÐÍ¡£</para>
      </listitem>

      <listitem>
	<para>ÈçºÎʹÓûù±¾¹¤¾ßÀ´ÅäÖú͹ÜÀí²»Í¬µÄ <acronym>RAID</acronym>
	  ¼¶±ð¡£</para>
      </listitem>

      <listitem>
        <para>ÈçºÎͨ¹ý GEOM ʹÓþµÏñ¡¢ Ìõ´ø¡¢ ¼ÓÃܺ͹ҽÓÔÚÔ¶³ÌµÄ´ÅÅÌÉ豸¡£</para>
      </listitem>

      <listitem>
	<para>ÈçºÎÅųý¹Ò½ÓÔÚ GEOM ¿ò¼ÜÉϵĴÅÅÌÉ豸µÄÎÊÌâ¡£</para>
      </listitem>
    </itemizedlist>

    <para>ÔĶÁÕâÕÂ֮ǰ£¬ ÄúÓ¦£º</para>

    <itemizedlist>
      <listitem>
	<para>Àí½â &os; ÈçºÎ´¦Àí´ÅÅÌÉ豸
	  (<xref linkend="disks"/>)¡£</para>
      </listitem>

      <listitem>
	<para>Á˽âÈçºÎÅäÖúͰ²×°Ð嵀 &os; ÄÚºË
	  (<xref linkend="kernelconfig"/>)¡£</para>
      </listitem>
    </itemizedlist>
  </sect1>

  <sect1 id="GEOM-intro">
    <title>GEOM ½éÉÜ</title>

    <para>GEOM ÔÊÐí·ÃÎʺͿØÖÆÀà (classes) &mdash; Ö÷Òýµ¼¼Ç¼¡¢
      <acronym>BSD</acronym> ±êÇ© (label)£¬ µÈµÈ &mdash; ͨ¹ýʹÓÃ
      provider£¬ »òÔÚ
      <filename class="directory">/dev</filename> ÖеÄÌØÊâÎļþ¡£
      ËüÖ§³ÖÐí¶àÈí¼þ <acronym>RAID</acronym> ÅäÖ㬠GEOM Äܹ»Ïò²Ù×÷ϵͳ£¬
      ÒÔ¼°ÔÚÆäÉÏÔËÐеŤ¾ßÌṩ͸Ã÷µÄ·ÃÎÊ·½Ê½¡£</para>
  </sect1>

  <sect1 id="GEOM-striping">
  <sect1info>
    <authorgroup>
      <author>
	<firstname>Tom</firstname>
	<surname>Rhodes</surname>
	<contrib>Ô­×÷ </contrib>
      </author>
      <author>
	<firstname>Murray</firstname>
	<surname>Stokely</surname>
      </author>
    </authorgroup>
  </sect1info>

    <title>RAID0 - Ìõ´ø</title>

    <indexterm>
      <primary>GEOM</primary>
    </indexterm>
    <indexterm>
      <primary>Ìõ´ø</primary>
    </indexterm>

    <para>Ìõ´øÊÇÒ»ÖÖ½«¶à¸ö´ÅÅÌÇý¶¯Æ÷ºÏ²¢ÎªÒ»¸ö¾íµÄ·½·¨¡£
      Ðí¶àÇé¿öÏ£¬ ÕâÊÇͨ¹ýÓ²¼þ¿ØÖÆÆ÷À´Íê³ÉµÄ¡£ GEOM
      ´ÅÅÌ×ÓϵͳÌṩÁË <acronym>RAID</acronym>0 µÄÈí¼þÖ§³Ö£¬
      ËüÒ²³ÉΪ´ÅÅÌÌõ´ø¡£</para>

    <para>ÔÚ <acronym>RAID</acronym>0 ϵͳÖУ¬ Êý¾Ý±»·ÖΪ¶à¸ö¿é£¬
      ÕâЩ¿é½«·Ö±ðдÈëÕóÁеÄËùÓдÅÅÌ¡£ ÓëÏÈÇ°ÐèÒªµÈ´ýϵͳ½« 256k
      Êý¾Ýдµ½Ò»¿é´ÅÅÌÉϲ»Í¬£¬ <acronym>RAID</acronym>0 ϵͳ£¬
      Äܹ»Í¬Ê±·Ö±ð½«´òËéµÄ 64k дµ½ËÄ¿é´ÅÅÌÉÏ£¬ ´Ó¶øÌṩ¸üºÃµÄ I/O
      ÐÔÄÜ¡£ ÕâÒ»ÐÔÄÜÌáÉý»¹Äܹ»Í¨¹ýʹÓöà¸ö´ÅÅÌ¿ØÖÆÆ÷À´½øÒ»²½¸Ä½ø¡£</para>

    <para>ÔÚ <acronym>RAID</acronym>0 Ìõ´øÖеÄÿһ¸öÅ̵ijߴç±ØÐëÒ»Ñù£¬
      ÒòΪ I/O ÇëÇóÊÇ·ÖÉ¢µ½¶à¸öÅÌÉϵģ¬ ÒÔ±ãÈÃÕâЩÅÌÉϵĶÁд²¢ÐÐÍê³É¡£</para>

      <mediaobject>
        <imageobject>
          <imagedata fileref="geom/striping" align="center"/>
        </imageobject>

        <textobject>
          <phrase>´ÅÅÌÌõ´øͼ</phrase>
        </textobject>
      </mediaobject>

    <procedure>
      <title>ÔÚδ¸ñʽ»¯µÄ ATA ´ÅÅÌÉϽ¨Á¢Ìõ´ø</title>

      <step><para>¼ÓÔØ <filename>geom_stripe.ko</filename>
        Ä£¿é£º</para>

    <screen>&prompt.root; <userinput>kldload geom_stripe</userinput></screen>
	</step>

      <step><para>È·ÐÅ´æÔÚºÏÊʵĹҽӵã (mount point)¡£ Èç¹ûÕâ¸ö¾í½«³ÉΪ¸ù·ÖÇø£¬
        ÄÇôÔÝʱ°ÑËü¹Ò½Óµ½ÆäËûλÖÃi£¬ Èç <filename
        class="directory">/mnt</filename>£º</para>

        <screen>&prompt.root; <userinput>mkdir /mnt</userinput></screen>
      </step>

      <step>
	<para>È·¶¨½«±»×ö³ÉÌõ´ø¾íµÄ´ÅÅ̵ÄÉ豸Ãû£¬
	  ²¢´´½¨ÐµÄÌõ´øÉ豸¡£ ¾ÙÀý¶øÑÔ£¬
	  Òª½«Á½¸öδÓõġ¢ ÉÐδ·ÖÇøµÄ <acronym>ATA</acronym> ´ÅÅÌ
	  <filename>/dev/ad2</filename> ºÍ
	  <filename>/dev/ad3</filename> ×ö³ÉÒ»¸öÌõ´øÉ豸£º</para>

        <screen>&prompt.root; <userinput>gstripe label -v st0 /dev/ad2 /dev/ad3</userinput>
Metadata value stored on /dev/ad2.
Metadata value stored on /dev/ad3.
Done.</screen>

      </step>

      <step>
	<para>½Ó×ÅÐèҪд±ê×¼µÄ label£¬ Ò²¾ÍÊÇͨ³£Ëù˵µÄ·ÖÇø±íµ½Ð¾íÉÏ£¬
	  ²¢°²×°±ê×¼µÄÒýµ¼´úÂ룺</para>

        <screen>&prompt.root; <userinput>bsdlabel -wB /dev/stripe/st0</userinput></screen>
      </step>

      <step>
	<para>ÉÏÊö¹ý³Ì½«ÔÚ
	  <filename class="directory">/dev/stripe</filename>
	  Ŀ¼ÖÐµÄ <devicename>st0</devicename> É豸»ù´¡ÉϽ¨Á¢Á½¸öÐÂÉ豸¡£
	  Õâ°üÀ¨ <devicename>st0a</devicename> ºÍ
	  <devicename>st0c</devicename>¡£ Õâʱ£¬ ¾Í¿ÉÒÔÔÚ
	  <devicename>st0a</devicename> É豸ÉÏÓÃÏÂÊö
	  <command>newfs</command> ÃüÁîÀ´½¨Á¢ÎļþϵͳÁË£º</para>

	<screen>&prompt.root; <userinput>newfs -U /dev/stripe/st0a</userinput></screen>

	<para>ÔÚÆÁÄ»ÉϽ«¹ö¹ýһЩÊý×Ö£¬ Õû¸ö²Ù×÷Ó¦¸ÃÄÜÔÚÊýÃëÄÚÍê³É¡£
	  ÏÖÔÚ¿ÉÒÔ¹Ò½Ó¸Õ¸Õ×öºÃµÄ¾íÁË¡£</para>
      </step>

  </procedure>

  <para>Òª¹Ò½Ó¸Õ´´½¨µÄÌõ´øÅÌ£º</para>

  <screen>&prompt.root; <userinput>mount /dev/stripe/st0a /mnt</userinput></screen>

    <para>ÒªÔÚÆô¶¯¹ý³ÌÖÐ×Ô¶¯¹Ò½ÓÕâ¸öÌõ´øÉϵÄÎļþϵͳ£¬
      ÐèÒª°Ñ¹ØÓÚ¾íµÄÐÅÏ¢·Åµ½
      <filename>/etc/fstab</filename> ÎļþÖС£Îª´ïµ½´ËÄ¿µÄ£¬
      ÐèÒª´´½¨Ò»¸ö½Ð
      <filename class="directory">stripe</filename>
      µÄÓÀ¾ÃµÄ¹ÒÔص㣺</para>

  <screen>&prompt.root; <userinput>mkdir /stripe</userinput>
&prompt.root; <userinput>echo "/dev/stripe/st0a /stripe ufs rw 2 2" \</userinput>
    <userinput>&gt;&gt; /etc/fstab</userinput></screen>

    <para>´ËÍ⣬ <filename>geom_stripe.ko</filename> Ä£¿éÒ²±ØÐëͨ¹ýÔÚ
      <filename>/boot/loader.conf</filename> ÖÐÔö¼ÓÏÂÊöÉèÖã¬
      ÒÔ±ãÔÚϵͳ³õʼ»¯¹ý³ÌÖÐ×Ô¶¯¼ÓÔØ£º</para>

  <screen>&prompt.root; <userinput>echo 'geom_stripe_load="YES"' &gt;&gt; /boot/loader.conf</userinput></screen>

  </sect1>

  <sect1 id="GEOM-mirror">
    <title>RAID1 - ¾µÏñ</title>

    <indexterm>
      <primary>GEOM</primary>
    </indexterm>
    <indexterm>
      <primary>´ÅÅ̾µÏñ</primary>
    </indexterm>

    <para>¾µÏñÊÇÐí¶à¹«Ë¾ºÍ¼ÒÍ¥Óû§Ê¹ÓõÄÒ»ÖÖÎÞÐëÖжϵı¸·Ý¼¼Êõ¡£
      ¼òµ¥µØ˵£¬ ¾µÏñµÄ¸ÅÄî¾ÍÊÇ ´ÅÅÌB ÊÇͬ²½¸´ÖÆ (replicate) µÄ ´ÅÅÌA µÄ¸±±¾£¬
      »òÕß ´ÅÅÌC+D ÊÇ diskA+B µÄͬ²½¸´ÖƸ±±¾£¬ µÈµÈ¡£ ÎÞÂÛ´ÅÅÌÅäÖÃÈçºÎ£¬
      ÕâÖÖ¼¼ÊõµÄ¹²Í¬Ìص㶼ÊÇÒ»¿é´ÅÅÌ»ò·ÖÇøµÄÄÚÈÝ»áͬ²½¸´ÖƵ½ÁíÍâµÄµØ·½¡£
      ÕâÑù£¬ ³ýÁËÄܹ»ºÜÈÝÒ׵ػָ´ÐÅÏ¢Ö®Í⣬
      »¹Äܹ»ÔÚÎÞÐëÖжϷþÎñ»ò·ÃÎʵÄÇé¿öϽøÐб¸·Ý£¬
      ÉõÖÁÖ±½Ó½«¸±±¾Ë͵½Êý¾Ý±£°²¹«Ë¾ÒìµØ´¢´æ¡£</para>

    <para>ÔÚ¿ªÊ¼×öÕâ¼þÊÂ֮ǰ£¬ Ê×ÏÈÇë×¼±¸Á½¸öÈÝÁ¿ÏàͬµÄ´ÅÅÌÇý¶¯Æ÷£¬
      ÏÂÃæµÄÀý×Ó¼Ù¶¨ËüÃǶ¼ÊÇʹÓÃÖ±½Ó·ÃÎÊ·½Ê½ (Direct Access£¬ &man.da.4;) µÄ
      <acronym>SCSI</acronym> ´ÅÅÌ¡£</para>

    <sect2>
      <title>¶ÔÖ÷´ÅÅ̽øÐоµÏñ</title>

      <para>¼Ù¶¨ÄúÏÖÓÐϵͳÖÐµÄ &os; °²×°µ½Á˵ÚÒ»¸ö£¬ Ò²¾ÍÊÇ
	<devicename>da0</devicename> ÅÌÉÏ£¬ ÔòÓ¦¸æËß &man.gmirror.8;
	½«Ö÷ÒªÊý¾Ý±£´æÔÚÕâÀï¡£</para>

      <para>ÔÚ¿ªÊ¼¹¹½¨¾µÏñ¾í֮ǰ£¬ ¿ÉÒÔÆôÓøü¶àµÄµ÷ÊÔÐÅÏ¢£¬
	²¢Ó¦¿ª·Å¶ÔÉ豸µÄÍêÈ«·ÃÎÊ¡£ Õâ¿ÉÒÔͨ¹ý½« &man.sysctl.8; ±äÁ¿
	<varname>kern.geom.debugflags</varname>
	ÉèÖÃΪÏÂÃæµÄÖµÀ´ÊµÏÖ£º</para>

      <screen>&prompt.root; <userinput>sysctl kern.geom.debugflags=17</userinput></screen>

      <para>½ÓÏÂÀ´ÐèÒª´´½¨¾µÏñ¡£ Õâ¸ö¹ý³ÌµÄµÚÒ»²½ÊÇÔÚÖ÷´ÅÅÌÉϱ£´æÔªÊý¾ÝÐÅÏ¢£¬
	Ò²¾ÍÊÇÓÃÏÂÃæµÄÃüÁîÀ´´´½¨
	<filename class="devicefile">/dev/mirror/gm</filename> É豸£º</para>

      <warning>
	<para>ÔÚÒýµ¼ÓõÄÉ豸»ù´¡ÉÏн¨¾µÏñʱ£¬
	  ÓпÉÄܻᵼÖ±£´æÔÚ´ÅÅÌÉÏ×îºóÒ»¸öÉÈÇøµÄÊý¾Ý¶ªÊ§¡£
	  ÔÚа²×° &os; Ö®ºóÁ¢¼´´´½¨¾µÏñ¿ÉÒÔ¼õµÍ´Ë·çÏÕ¡£
	  ÏÂÃæµÄ²Ù×÷ÓëĬÈ쵀 &os;&nbsp;9.<replaceable>X</replaceable>
	  °²×°¹ý³Ì²»¼æÈÝ£¬ ÒòΪËü²ÉÓÃÁËÐ嵀 <acronym>GPT</acronym>
	  ·ÖÇø¸ñʽ¡£ GEOM »á¸²¸Ç <acronym>GPT</acronym> ÔªÊý¾Ý£¬
	  Õâ»áµ¼ÖÂÊý¾Ý¶ªÊ§£¬ ²¢ÓпÉÄܵ¼ÖÂϵͳÎÞ·¨Òýµ¼¡£</para>
      </warning>

      <screen>&prompt.root; <userinput>gmirror label -vb round-robin gm0 /dev/da0</userinput></screen>

      <para>ϵͳӦ¸ø³öÏÂÃæµÄ»ØÓ¦£º</para>

      <screen>Metadata value stored on /dev/da0.
Done.</screen>

      <para>³õʼ»¯ GEOM£¬ Õâ²½²Ù×÷»á¼ÓÔØÄÚºËÄ£¿é
	<filename>/boot/kernel/geom_mirror.ko</filename>£º</para>

      <screen>&prompt.root; <userinput>gmirror load</userinput></screen>

      <note>
	<para>µ±Õâ¸öÃüÁîÔËÐÐÍêÖ®ºó£¬ ϵͳ»áÔÚ
	  <filename class="directory">/dev/mirror</filename>
	  Ŀ¼Öд´½¨É豸½Úµã
	  <devicename>gm0</devicename>¡£</para>
      </note>

      <para>ÅäÖÃÔÚϵͳ³õʼ»¯¹ý³ÌÖÐ×Ô¶¯¼ÓÔØ <filename>geom_mirror.ko</filename>£º</para>

      <screen>&prompt.root; <userinput>echo 'geom_mirror_load="YES"' &gt;&gt; /boot/loader.conf</userinput></screen>

      <para>±à¼­ <filename>/etc/fstab</filename> Îļþ£¬
	½«ÆäÖÐÏÈÇ°µÄ <devicename>da0</devicename> ¸ÄΪеľµÏñÉ豸
	<devicename>gm0</devicename>¡£</para>

      <note>
        <para>Èç¹û &man.vi.1; ÊÇÄãϲ»¶µÄ±à¼­Æ÷£¬
          ÒÔÏÂÔòÊÇÍê³É´ËÏîÈÎÎñµÄÒ»¸ö¼ò±ã·½·¨£º</para>

        <screen>&prompt.root; <userinput>vi /etc/fstab</userinput></screen>

	<para>ÔÚ &man.vi.1; Öб¸·ÝÏÖÓеÄ
	  <filename>fstab</filename> ÄÚÈÝ£¬ ¾ßÌå²Ù×÷ÊÇ
	  <userinput>:w /etc/fstab.bak</userinput>¡£ ½Ó×Å£¬
	  °ÑËùÓÐ¾ÉµÄ <devicename>da0</devicename>
	  Ìæ»»³É <devicename>gm0</devicename>£¬ Ò²¾ÍÊÇÊäÈëÃüÁî
	  <userinput>:%s/da/mirror\/gm/g</userinput>¡£</para>
      </note>

      <para>ÐÞ¸ÄÍêºóµÄ <filename>fstab</filename> ÎļþÓ¦¸ÃÊÇÏÂÃæµÄÑù×Ó¡£
	´ÅÅÌÇý¶¯Æ÷ÊÇ <acronym>SCSI</acronym> »ò <acronym>ATA</acronym>
	ÉõÖÁ <acronym>RAID</acronym> ¶¼Ã»ÓйØϵ£¬ ×îÖյĽá¹û¶¼ÊÇ
	<devicename>gm</devicename>¡£</para>

      <programlisting># Device		Mountpoint	FStype	Options		Dump	Pass#
/dev/mirror/gm0s1b	none		swap	sw		0	0
/dev/mirror/gm0s1a	/		ufs	rw		1	1
/dev/mirror/gm0s1d	/usr		ufs	rw		0	0
/dev/mirror/gm0s1f	/home		ufs	rw		2	2
#/dev/mirror/gm0s2d	/store		ufs	rw		2	2
/dev/mirror/gm0s1e	/var		ufs	rw		2       2
/dev/acd0		/cdrom		cd9660	ro,noauto	0	0</programlisting>

      <para>ÖØÆôϵͳ£º</para>

      <screen>&prompt.root; <userinput>shutdown -r now</userinput></screen>

      <para>ÔÚϵͳ³õʼ»¯¹ý³ÌÖУ¬ н¨µÄ
	<devicename>gm0</devicename> »á´úÌæ
	<devicename>da0</devicename> É豸¹¤×÷¡£ ϵͳÍê³É³õʼ»¯Ö®ºó£¬
	¿ÉÒÔͨ¹ý¼ì²é <command>mount</command> ÃüÁîµÄÊä³öÀ´²é¿´Ð§¹û£º</para>

      <screen>&prompt.root; <userinput>mount</userinput>
Filesystem         1K-blocks    Used    Avail Capacity  Mounted on
/dev/mirror/gm0s1a   1012974  224604   707334    24%    /
devfs                      1       1        0   100%    /dev
/dev/mirror/gm0s1f  45970182   28596 42263972     0%    /home
/dev/mirror/gm0s1d   6090094 1348356  4254532    24%    /usr
/dev/mirror/gm0s1e   3045006 2241420   559986    80%    /var
devfs                      1       1        0   100%    /var/named/dev</screen>

      <para>Õâ¸öÊä³öÊÇÕý³£µÄ¡£ ×îºó£¬ ʹÓÃÏÂÃæµÄÃüÁ <devicename>da1</devicename>
	´ÅÅ̼ӵ½¾µÏñ¾íÖУ¬ ÒÔ¿ªÊ¼Í¬²½¹ý³Ì£º</para>

      <screen>&prompt.root; <userinput>gmirror insert gm0 /dev/da1</userinput></screen>

      <para>ÔÚ¹¹½¨¾µÏñ¾íµÄ¹ý³ÌÖУ¬ ¿ÉÒÔÓÃÏÂÃæµÄÃüÁî²é¿´×´Ì¬£º</para>

      <screen>&prompt.root; <userinput>gmirror status</userinput></screen>

      <para>Ò»µ©¾µÏñ¾íµÄ¹¹½¨²Ù×÷Íê³É£¬ Õâ¸öÃüÁîµÄÊä³ö¾Í»á±ä³ÉÕâÑù£º</para>

      <screen>      Name    Status  Components
mirror/gm0  COMPLETE  da0
                      da1</screen>

      <para>Èç¹ûÓÐÎÊÌâ»òÕß¹¹½¨ÈÔÔÚ½øÐУ¬ Êä³öÖеÄ
	<literal>COMPLETE</literal> ¾Í»áÊÇ
	<literal>DEGRADED</literal>¡£</para>
    </sect2>

    <sect2>
      <title>¹ÊÕÏÅųý</title>
      <sect3>
	<title>ϵͳ¾Ü¾øÒýµ¼</title>

	<para>Èç¹ûϵͳÒýµ¼Ê±³öÏÖÀàËÆÏÂÃæµÄÌáʾ£º</para>

	<programlisting>ffs_mountroot: can't find rootvp
Root mount failed: 6
mountroot></programlisting>

	<para>ÕâÖÖÇé¿öӦʹÓõçÔ´»ò¸´Î»°´Å¥ÖØÆô»úÆ÷¡£
	  ÔÚÒýµ¼²Ëµ¥ÖУ¬ Ñ¡ÔñµÚÁù (6) ¸öÑ¡Ïî¡£
	  Õ⽫ÈÃϵͳ½øÈë &man.loader.8; Ìáʾ·û¡£
	  ÔÚ´Ë´¦ÊÖ¹¤¼ÓÔØÄÚºËÄ£¿é£º</para>

	<screen>OK? <userinput>load geom_mirror</userinput>
OK? <userinput>boot</userinput></screen>

	<para>Èç¹ûÕâÑù×öÄܽâ¾öÎÊÌ⣬ Ôò˵Ã÷ÓÉÓÚijÖÖÔ­ÒòÄ£¿éûÓб»ÕýÈ·¼ÓÔØ¡£
	  ¼ì²é <filename>/boot/loader.conf</filename> ÖÐÏà¹ØÌõÄ¿ÊÇ·ñÕýÈ·¡£
	  Èç¹ûÎÊÌâÈÔÈ»´æÔÚ£¬¿ÉÒÔÔÚÄÚºËÅäÖÃÎļþÖмÓÈ룺</para>

	<programlisting>options	GEOM_MIRROR</programlisting>

	<para>È»ºóÖØбàÒëºÍ°²×°ÄÚºËÀ´½â¾öÕâ¸öÎÊÌâ¡£</para>
      </sect3>
    </sect2>

    <sect2>
      <title>´Ó´ÅÅ̹ÊÕÏÖлָ´</title>

      <para>´ÅÅ̾µÏñµÄÒ»´óºÃ´¦ÊÇÔÚµ±ÆäÖÐÒ»¸ö´ÅÅ̳öÏÖ¹ÊÕÏʱ£¬
	¿ÉÒÔºÜÈÝÒ׵ؽ«ÆäÌæ»»µô£¬ ²¢ÇÒͨ³£²»»á¶ªÊ§Êý¾Ý¡£</para>

      <para>¿¼ÂÇÇ°ÃæµÄ <acronym>RAID</acronym>1
	ÅäÖ㬠¼ÙÉè <devicename>da1</devicename>
	³öÏÖÁ˹ÊÕϲ¢ÐèÒªÌæ»»£¬ ÒªÌæ»»Ëü£¬
	Ê×ÏÈÈ·¶¨Äĸö´ÅÅ̳öÏÖÁ˹ÊÕÏ£¬ ²¢¹Ø±Õϵͳ¡£
	´Ëʱ£¬ ¿ÉÒÔÓû»ÉÏеĴÅÅÌ£¬ ²¢ÖØÐÂÆô¶¯ÏµÍ³¡£
	ÕâÖ®ºó¿ÉÒÔÓÃÏÂÃæµÄÃüÁîÀ´Íê³É´ÅÅ̵ÄÌæ»»²Ù×÷£º</para>

      <screen>&prompt.root; <userinput>gmirror forget gm0</userinput></screen>

      <screen>&prompt.root; <userinput>gmirror insert gm0 /dev/da1</userinput></screen>

      <para>ÔÚÖؽ¨¹ý³ÌÖпÉÒÔÓà <command>gmirror</command> <option>status</option>
	ÃüÁîÀ´¼à¿´½ø¶È¡£ ¾ÍÊÇÕâÑù¼òµ¥¡£</para>
    </sect2>
  </sect1>

  <sect1 id="GEOM-raid3">
    <sect1info>
      <authorgroup>
	<author>
	  <firstname>Mark</firstname>
	  <surname>Gladman</surname>
	  <contrib>Written by </contrib>
	</author>
	<author>
	  <firstname>Daniel</firstname>
	  <surname>Gerzo</surname>
	</author>
      </authorgroup>
      <authorgroup>
	<author>
	  <firstname>Tom</firstname>
	  <surname>Rhodes</surname>
	  <contrib>Based on documentation by </contrib>
	</author>
	<author>
	  <firstname>Murray</firstname>
	  <surname>Stokely</surname>
	</author>
      </authorgroup>
    </sect1info>

    <title><acronym>RAID</acronym>3 - ʹÓÃרÓÃУÑéÉ豸µÄ×Ö½Ú¼¶Ìõ´ø</title>

    <indexterm>
      <primary>GEOM</primary>
    </indexterm>
    <indexterm>
      <primary>RAID3</primary>
    </indexterm>

    <para><acronym>RAID</acronym>3 ÊÇÒ»ÖÖ½«¶à¸ö´ÅÅÌ×é³ÉÒ»¸ö¾íµÄ¼¼Êõ£¬
      ÔÚÕâ¸öÅäÖÃÖаüº¬Ò»¸öרÓÃÓÚУÑéµÄÅÌ¡£
      ÔÚ <acronym>RAID</acronym>3 ϵͳÖУ¬
      Êý¾Ý»áÒÔ×Ö½ÚΪµ¥Î»²ð·Ö²¢Ð´Èë³ýУÑéÅÌÖ®ÍâµÄÈ«²¿Çý¶¯Æ÷ÖС£ ÕâÒâζ×Å´Ó
      <acronym>RAID</acronym>3 ÖжÁÈ¡Êý¾Ýʱ½«»á·ÃÎÊËùÓеÄÇý¶¯Æ÷¡£
      ²ÉÓöà¸ö´ÅÅÌ¿ØÖÆÆ÷¿ÉÒÔ½øÒ»²½¸ÄÉÆÐÔÄÜ¡£ <acronym>RAID</acronym>3
      ÕóÁÐ×î¶à¿ÉÒÔÈÝÈÌÆäÖÐµÄ 1 ¸öÇý¶¯Æ÷³öÏÖ¹ÊÕÏ£¬
      Ëü¿ÉÒÔÌṩȫ²¿Çý¶¯Æ÷×ÜÈÝÁ¿µÄ 1 - 1/n£¬
      ´Ë´¦ n ÊÇÕóÁÐÖеĴÅÅÌÊýÁ¿¡£ ÕâÀàÅäÖñȽÏÊʺϱ£´æ´óÈÝÁ¿µÄÊý¾Ý£¬
      ÀýÈç¶àýÌåÎļþ¡£</para>

    <para>ÔÚ½¨Á¢
      <acronym>RAID</acronym>3 ÕóÁÐʱ£¬ ÖÁÉÙÐèÒª 3 ¿é´ÅÅÌ¡£
      ËùÓеÄÅ̵ijߴç±ØÐëÒ»Ö£¬ ÒòΪ I/O ÇëÇó»á²¢·¢·ÖÅɵ½²»Í¬µÄÅÌÉÏ¡£
      ÁíÍ⣬ ÓÉÓÚ
      <acronym>RAID</acronym>3 ±¾ÉíµÄÉè¼Æ£¬
      Å̵ÄÊýÁ¿±ØÐëÇ¡ºÃÊÇ 3, 5, 9, 17, µÈµÈ (2^n + 1)¡£</para>

    <sect2>
      <title>½¨Á¢×¨ÓÃµÄ <acronym>RAID</acronym>3 ÕóÁÐ</title>

      <para>ÔÚ &os; ÖУ¬ <acronym>RAID</acronym>3
	ÊÇͨ¹ý &man.graid3.8; <acronym>GEOM</acronym>
	class ʵÏֵġ£ ÔÚ &os; Öн¨Á¢×¨ÓõÄ
	<acronym>RAID</acronym>3 ÕóÁÐÐèÒªÏÂÊö²½Öè¡£</para>

      <note>
	<para>ËäÈ»ÀíÂÛÉÏ´Ó
	  <acronym>RAID</acronym>3 ÕóÁÐÆô¶¯ &os; ÊÇ¿ÉÐеģ¬
	  µ«Õâ²¢²»³£¼û£¬ Ò²²»ÍƼöÄúÕâÑù×ö¡£</para>
      </note>

      <procedure>
	<step>
	  <para>Ê×ÏÈ£¬ ÔÚÒýµ¼¼ÓÔØÆ÷ÖÐÓÃÏÂÃæµÄÃüÁî¼ÓÔØ <filename>geom_raid3.ko</filename>
	    ÄÚºËÄ£¿é£º</para>

	  <screen>&prompt.root; <userinput>graid3 load</userinput></screen>

	  <para>´ËÍ⣬ Ò²¿ÉÒÔͨ¹ýÃüÁîÐÐÊÖ¹¤¼ÓÔØ
	    <filename>geom_raid3.ko</filename> Ä£¿é£º</para>

	  <screen>&prompt.root; <userinput>kldload geom_raid3.ko</userinput></screen>
	</step>

	<step>
	  <para>´´½¨ÓÃÓÚ¹ÒÔؾíµÄ¹ÒµãĿ¼£º</para>

	  <screen>&prompt.root; <userinput>mkdir <replaceable>/multimedia/</replaceable></userinput></screen>
	</step>

	<step>
	  <para>È·¶¨½«Òª¼ÓÈëÕóÁеĴÅÅÌÉ豸Ãû£¬ ²¢´´½¨ÐµÄ
	    <acronym>RAID</acronym>3 É豸¡£ ×îÖÕ£¬ Õâ¸öÉ豸½«´ú±íÕû¸öÕóÁС£
	    ÏÂÃæµÄÀý×ÓʹÓÃÈý¸öδ¾­·ÖÇøµÄ
	    <acronym>ATA</acronym> ´ÅÅÌ£º
	    <devicename><replaceable>ada1</replaceable></devicename>
	    ºÍ <devicename><replaceable>ada2</replaceable></devicename>
	    ±£´æÊý¾Ý£¬ ¶ø
	    <devicename><replaceable>ada3</replaceable></devicename>
	    ÓÃÓÚУÑé¡£</para>

	  <screen>&prompt.root; <userinput>graid3 label -v gr0 /dev/ada1 /dev/ada2 /dev/ada3</userinput>
Metadata value stored on /dev/ada1.
Metadata value stored on /dev/ada2.
Metadata value stored on /dev/ada3.
Done.</screen>
	</step>

	<step>
	  <para>Ϊн¨µÄ
	    <devicename>gr0</devicename> É豸·ÖÇø£¬
	    ²¢ÔÚÆäÉÏ´´½¨ UFS Îļþϵͳ£º</para>

	  <screen>&prompt.root; <userinput>gpart create -s GPT /dev/raid3/gr0</userinput>
&prompt.root; <userinput>gpart add -t freebsd-ufs /dev/raid3/gr0</userinput>
&prompt.root; <userinput>newfs -j /dev/raid3/gr0p1</userinput></screen>

	  <para>ÆÁÄ»ÉÏ»á¹ö¹ýÐí¶àÊý×Ö£¬ Õâ¸ö¹ý³ÌÐèÒªÒ»¶Îʱ¼ä²ÅÄÜÍê³É¡£
	    ´Ëºó£¬ Äú¾ÍÍê³ÉÁË´´½¨¾íµÄÈ«²¿²Ù×÷£¬
	    ¿ÉÒÔ¹ÒÔØËüÁË¡£</para>
	</step>

	<step>
	  <para>×îºóÒ»²½ÊǹÒÔØÎļþϵͳ£º</para>

	  <screen>&prompt.root; <userinput>mount /dev/raid3/gr0p1 /multimedia/</userinput></screen>

	  <para>ÏÖÔÚ¿ÉÒÔʹÓà <acronym>RAID</acronym>3 ÕóÁÐÁË¡£</para>
	</step>
      </procedure>

      <para>ΪÁËÈÃÉÏÊöÅäÖÃÔÚϵͳÖØÆôºó¼ÌÐø¿ÉÓ㬠»¹ÐèÒª½øÐÐһЩ¶îÍâµÄÅäÖòÙ×÷¡£</para>

      <procedure>
	<step>
	  <para>ÔÚ¹ÒÔؾí֮ǰ±ØÐëÊ×ÏȼÓÔØ <filename>geom_raid3.ko</filename> Ä£¿é¡£
	    ½«ÏÂÃæµÄÅäÖÃÌí¼Óµ½
	    <filename>/boot/loader.conf</filename> ÎļþÖУ¬
	    ¿ÉÒÔÈÃϵͳÔÚÒýµ¼¹ý³ÌÖÐ×Ô¶¯¼ÓÔØÕâ¸öÄ£¿é£º</para>

	  <programlisting>geom_raid3_load="YES"</programlisting>
	</step>

	<step>
	  <para>ÄúÐèÒªÔÚ
	    <filename>/etc/fstab</filename> ÎļþÖмÓÈëÏÂÁÐÅäÖã¬
	    ÒÔ±ãÈÃϵͳÒýµ¼Ê±×Ô¶¯¹ÒÔØÕóÁÐÉϵÄÎļþϵͳ£º</para>

	  <programlisting>/dev/raid3/gr0p1	/multimedia	ufs	rw	2	2</programlisting>
	</step>
      </procedure>
    </sect2>
  </sect1>

  <sect1 id="geom-ggate">
    <title>GEOM Gate ÍøÂçÉ豸</title>

    <para>ͨ¹ý gate ¹¤¾ß£¬ GEOM Ö§³ÖÒÔÔ¶³Ì·½Ê½Ê¹ÓÃÉ豸£¬ ÀýÈç´ÅÅÌ¡¢
      CD-ROM¡¢ ÎļþµÈµÈ¡£ ÕâºÍ <acronym>NFS</acronym> ÀàËÆ¡£</para>

    <para>ÔÚ¿ªÊ¼¹¤×÷֮ǰ£¬ Ê×ÏÈÒª´´½¨Ò»¸öµ¼³öÎļþ¡£
      Õâ¸öÎļþµÄ×÷ÓÃÊÇÖ¸¶¨Ë­¿ÉÒÔ·ÃÎʵ¼³öµÄ×ÊÔ´£¬
      ÒÔ¼°ÌṩºÎÖÖ¼¶±ðµÄ·ÃÎÊÊÚȨ¡£ ÀýÈ磬
      Òª°ÑµÚÒ»¿é <acronym>SCSI</acronym> Å̵ĵÚËĸö slice µ¼³ö£¬
      ¶ÔÓ¦µÄ <filename>/etc/gg.exports</filename> »áÊÇÀàËÆÏÂÃæµÄÑù×Ó£º</para>

    <programlisting>192.168.1.0/24 RW /dev/da0s4d</programlisting>

    <para>Õâ±íʾÔÊÐíͬÊô˽ÓÐ×ÓÍøµÄËùÓлúÆ÷·ÃÎÊ
      <devicename>da0s4d</devicename> ·ÖÇøÉϵÄÎļþϵͳ¡£</para>

    <para>Òªµ¼³öÕâ¸öÉ豸£¬ Ê×ÏÈÇëÈ·ÈÏËüûÓб»¹Ò½Ó£¬
      È»ºóÊÇÆô¶¯ &man.ggated.8; ·þÎñ£º</para>

    <screen>&prompt.root; <userinput>ggated</userinput></screen>

    <para>ÏÖÔÚÎÒÃǽ«ÔÚ¿Í»§»úÉÏ <command>mount</command> ¸ÃÉ豸£¬
      ʹÓÃÏÂÃæµÄÃüÁ</para>

    <screen>&prompt.root; <userinput>ggatec create -o rw 192.168.1.1 /dev/da0s4d</userinput>
ggate0
&prompt.root; <userinput>mount /dev/ggate0 /mnt</userinput></screen>

    <para>µ½´ËΪֹ£¬ É豸Ӧ¸ÃÒѾ­¿ÉÒÔͨ¹ý¹Ò½Óµã
      <filename class="directory">/mnt</filename> ·ÃÎÊÁË¡£</para>

    <note>
      <para>Çë×¢Ò⣬ Èç¹ûÉ豸ÒѾ­±»·þÎñÆ÷»òÍøÂçÉϵÄÈκÎÆäËû»úÆ÷¹Ò½Ó£¬
	ÔòÇ°Êö²Ù×÷½«»áʧ°Ü¡£</para>
    </note>

    <para>Èç¹û²»ÔÙÐèҪʹÓÃÕâ¸öÉ豸£¬
      ¾Í¿ÉÒÔʹÓà &man.umount.8; ÃüÁîÀ´°²È«µØ½«ÆäжÏÂÁË£¬
      ÕâÒ»µãºÍÆäËû´ÅÅÌÉ豸ÀàËÆ¡£</para>
  </sect1>

  <sect1 id="geom-glabel">
    <title>Ϊ´ÅÅÌÉ豸Ìí¼Ó¾í±ê</title>

    <indexterm>
      <primary>GEOM</primary>
    </indexterm>
    <indexterm>
      <primary>´ÅÅ̾í±ê</primary>
    </indexterm>

    <para>ÔÚϵͳ³õʼ»¯µÄ¹ý³ÌÖУ¬ &os; Äں˻áΪ¼ì²âµ½µÄÉ豸´´½¨É豸½Úµã¡£
      ÕâÖÖ¼ì²â·½Ê½´æÔÚһЩÎÊÌ⣬ ÀýÈ磬
      ÔÚͨ¹ý <acronym>USB</acronym> Ìí¼ÓÉ豸ʱӦÈçºÎ´¦Àí£¿
      ºÜ¿ÉÄÜÓÐÉÁ´æÅÌÉ豸×î³õ±»Ê¶±ðΪ
      <devicename>da0</devicename> ¶øÔÚÕâÖ®ºó£¬ ÔòÓÉ
      <devicename>da0</devicename> ±ä³ÉÁË
      <devicename>da1</devicename>¡£ ¶øÕâÔò»áÔÚ¹Ò½Ó
      <filename>/etc/fstab</filename> ÖеÄÎļþϵͳʱÔì³ÉÎÊÌ⣬
      ÕâЩÎÊÌ⣬ »¹¿ÉÄÜÔÚϵͳÒýµ¼Ê±µ¼ÖÂÎÞ·¨Õý³£Æô¶¯¡£</para>

    <para>½â¾öÕâ¸öÎÊÌâµÄÒ»¸ö·½·¨ÊÇÒÔÁ¬½ÓÍØÆË·½Ê½Á´Ê½µØ½øÐÐ
      <acronym>SCSI</acronym> É豸ÃüÃû£¬ ÕâÑù£¬
      µ±ÔÚ <acronym>SCSI</acronym> ¿¨ÉÏÔö¼ÓÐÂÉ豸ʱ£¬ ÕâЩÉ豸½«Ê¹ÓÃÒ»¸öδÓõıàºÅ¡£
      µ«Èç¹û <acronym>USB</acronym> É豸ȡ´úÁËÖ÷ <acronym>SCSI</acronym> ´ÅÅ̵ÄλÖÃÄØ£¿
      ÓÉÓÚ <acronym>USB</acronym> ͨ³£»áÔÚ <acronym>SCSI</acronym> ¿¨Ö®Ç°¼ì²âµ½£¬
      Òò´ËºÜ¿ÉÄܳöÏÖÕâÖÖÏÖÏó¡£ µ±È»£¬ ¿ÉÒÔͨ¹ýÔÚϵͳÒýµ¼Ö®ºóÔÙ²åÈëÕâЩÉ豸À´ÈƹýÕâ¸öÎÊÌâ¡£
      ÁíÒ»ÖÖÈƹýÕâ¸öÎÊÌâµÄ·½·¨£¬ ÔòÊÇֻʹÓÃ
      <acronym>ATA</acronym> Çý¶¯Æ÷£¬ ²¢±ÜÃâÔÚ
      <filename>/etc/fstab</filename> ÖÐÁгö
      <acronym>SCSI</acronym> É豸¡£</para>

    <para>»¹ÓÐÒ»ÖÖ¸üºÃµÄ½â¾ö·½·¨¡£ ͨ¹ýʹÓÃ
      <command>glabel</command> ¹¤¾ß£¬ ¹ÜÀíÔ±»òÓû§¿ÉÒÔΪ´ÅÅÌÉ豸´òÉϱêÇ©£¬ ²¢ÔÚ
      <filename>/etc/fstab</filename> ÖÐʹÓÃÕâЩ±êÇ©¡£ ÓÉÓÚ
      <command>glabel</command> »á½«±êÇ©±£´æÔÚ¶ÔÓ¦ provider µÄ×îºóÒ»¸öÉÈÇø£¬
      ÔÚϵͳÖØÆôÖ®ºó£¬ ËüÈÔ»á³ÖÐø´æÔÚ¡£ Òò´Ë£¬ ͨ¹ý½«¾ßÌåµÄÉ豸Ì滻ΪʹÓñêÇ©±íʾ£¬
      ÎÞÂÛÉ豸½Úµã±ä³Éʲô£¬ Îļþϵͳ¶¼Äܹ»Ë³ÀûµØÍê³É¹Ò½Ó¡£</para>

    <note>
      <para>Õâ²¢²»ÊÇ˵±êÇ©Ò»¶¨ÊÇÓÀ¾ÃÐԵġ£
	<command>glabel</command> ¹¤¾ß¼È¿ÉÒÔ´´½¨ÓÀ¾ÃÐÔ±êÇ©£¬ Ò²¿ÉÒÔ´´½¨ÁÙʱÐÔ±êÇ©¡£
	ÔÚÖØÆôʱ£¬ Ö»ÓÐÓÀ¾ÃÐÔ±êÇ©»á±£³Ö¡£ Çë²Î¼ûÁª»úÊÖ²á &man.glabel.8;
	ÒÔÁ˽âÁ½ÕßÖ®¼äµÄ²îÒì¡£</para>
    </note>

    <sect2>
      <title>±êÇ©ÀàÐͺÍʹÓÃʾ·¶</title>

      <para>ÓÐÁ½ÖÖÀàÐ͵ıêÇ©£¬ Ò»ÖÖÊÇÆÕͨ±êÇ©£¬ ÁíÒ»ÖÖÊÇÎļþϵͳ±êÇ©¡£
	±êÇ©¿ÉÒÔÊÇÓÀ¾ÃÐԵĻòÔÝʱÐԵġ£ÓÀ¾ÃÐԵıêÇ©¿ÉÒÔͨ¹ý 
	&man.tunefs.8; »ò &man.newfs.8; ÃüÁî´´¼ü¡£¸ù¾ÝÎļþϵͳµÄÀàÐÍ£¬
	ËüÃǽ«ÔÚ <filename class="directory">/dev</filename>
	ϵÄÒ»¸ö×ÓĿ¼Öб»´´½¨¡£ÀýÈ磬
	<acronym>UFS</acronym>2 ÎļþϵͳµÄ±êÇ©»á´´½¨µ½
	<filename class="directory">/dev/ufs</filename>
	Ŀ¼ÖС£ÓÀ¾ÃÐԵıêÇ©»¹¿ÉÒÔʹÓà <command>glabel label</command>
	´´½¨¡£ËüÃDz»ÔÙÊÇÎļþϵͳÌض¨µÄ£¬¶øÊÇ»áÔÚ
	<filename class="directory">/dev/label</filename>
	Ŀ¼Öб»´´½¨¡£</para>

      <para>ÔÝʱÐԵıêÇ©ÔÚϵͳÏ´ÎÖØÆôʱ»áÏûʧ£¬ ÕâЩ±êÇ©»á´´½¨µ½
	<filename class="directory">/dev/label</filename> Ŀ¼ÖУ¬
	ºÜÊʺϲâÊÔÖ®Ó᣿ÉÒÔʹÓà <command>glabel create</command>
	´´½¨ÔÝʱÐԵıêÇ©¡£Çë²ÎÔÄ &man.glabel.8;
	ÊÖ²áÒ³ÒÔ»ñÈ¡¸ü¶àÏêϸÐÅÏ¢¡£</para>

<!-- XXXTR: How do you create a file system label without running newfs
	    or when there is no newfs (e.g.: cd9660)? -->

      <para>ҪΪһ¸ö <acronym>UFS</acronym>2 Îļþϵͳ´´½¨ÓÀ¾ÃÐÔ±êÇ©£¬
        ¶ø²»ÆÆ»µÆäÉϵÄÊý¾Ý£¬¿ÉÒÔʹÓÃÏÂÃæµÄÃüÁ</para>

      <screen>&prompt.root; <userinput>tunefs -L <replaceable>home</replaceable> <replaceable>/dev/da3</replaceable></userinput></screen>

      <warning>
	<para>Èç¹ûÎļþϵͳÂúÁË£¬ Õâ¿ÉÄܻᵼÖÂÊý¾ÝË𻵣» ²»¹ý£¬ Èç¹ûÎļþϵͳ¿ìÂúÁË£¬
	  ´ËʱӦÊ×ÏÈɾ³ýһЩÎÞÓõÄÎļþ£¬ ¶ø²»ÊÇÔö¼Ó±êÇ©¡£</para>
      </warning>

      <para>ÏÖÔÚ£¬ ÄúÓ¦¿ÉÒÔÔÚ
	<filename class="directory">/dev/ufs</filename> Ŀ¼Öп´µ½±êÇ©£¬
	²¢½«Æä¼ÓÈë <filename>/etc/fstab</filename>£º</para>

      <programlisting>/dev/ufs/home		/home            ufs     rw              2      2</programlisting>

      <note>
	<para>µ±ÔËÐÐ <command>tunefs</command> ʱ£¬ Ó¦Ê×ÏÈжÏÂÎļþϵͳ¡£</para>
      </note>

      <para>ÏÖÔÚ¿ÉÒÔÏñƽʱһÑù¹Ò½ÓÎļþϵͳÁË£º</para>

      <screen>&prompt.root; <userinput>mount /home</userinput></screen>

      <para>ÏÖÔÚ£¬ Ö»ÒªÔÚϵͳÒýµ¼Ê±Í¨¹ý <filename>/boot/loader.conf</filename> ÅäÖüÓÔØÁËÄÚºËÄ£¿é
	<filename>geom_label.ko</filename>£¬ »òÔÚÁª±àÄÚºËʱָ¶¨ÁË
	<literal>GEOM_LABEL</literal> Ñ¡Ï
	É豸½ÚµãÓÉÓÚÔöɾÉ豸¶ø˳Ðò·¢Éú±ä»¯Ê±£¬ ¾Í²»»áÓ°ÏìÎļþϵͳµÄ¹Ò½ÓÁË¡£</para>

      <para>ͨ¹ýʹÓà <command>newfs</command> ÃüÁîµÄ
	<option>-L</option> ²ÎÊý£¬ ¿ÉÒÔÔÚ´´½¨ÎļþϵͳʱΪÆäÌí¼ÓĬÈϵıêÇ©¡£
	Çë²Î¼ûÁª»úÊÖ²á &man.newfs.8; ÒÔÁ˽â½øÒ»²½µÄÏêÇé¡£</para>

      <para>ÏÂÁÐÃüÁî¿ÉÒÔÇå³ý±êÇ©£º</para>

      <screen>&prompt.root; <userinput>glabel destroy home</userinput></screen>

      <para>ÒÔϵÄÀý×ÓչʾÁËÈçºÎΪһ¸öÆô¶¯´ÅÅÌ´òÉϱêÇ©¡£</para>

      <example>
        <title>ΪÆô¶¯´ÅÅÌ´òÉϱêÇ©</title>

	<para>ΪÆô¶¯´ÅÅÌ´òÉÏÓÀ¾ÃÐÔ±êÇ©£¬ ϵͳӦ¸ÃÄܹ»Õý³£Æô¶¯£¬
	  ¼´Ê¹´ÅÅ̱»Òƶ¯µ½ÁËÁíÍâÒ»¸ö¿ØÖÆÆ÷»òÕßתÒƵ½ÁËÒ»¸ö²»Í¬µÄϵͳÉÏ¡£
	  ´ËÀýÖÐÎÒÃǼÙÉèʹÓÃÁËÒ»¸ö <acronym>ATA</acronym> ´ÅÅÌ£¬
	  µ±Ç°Õâ¸öÉ豸±»ÏµÍ³Ê¶±ðΪ <devicename>ad0</devicename>¡£
	  »¹¼ÙÉèʹÓÃÁ˱ê×¼µÄ &os; ·ÖÇø»®·Ö·½°¸£¬
	  <filename class="directory">/</filename>,
	  <filename class="directory">/var</filename>,
	  <filename class="directory">/usr</filename> ºÍ
	  <filename class="directory">/tmp</filename> Îļþϵͳ£¬
	  »¹ÓÐÒ»¸ö swap ·ÖÇø¡£</para>

	<para>ÖØÆôϵͳ£¬ÔÚ &man.loader.8; Ìáʾ·ûϼüÈë
	  <keycap>4</keycap> Æô¶¯µ½µ¥Óû§Ä£Ê½¡£
	  È»ºóÊäÈëÒÔϵÄÃüÁ</para>

	<screen>&prompt.root; <userinput>glabel label rootfs /dev/ad0s1a</userinput>
GEOM_LABEL: Label for provider /dev/ad0s1a is label/rootfs
&prompt.root; <userinput>glabel label var /dev/ad0s1d</userinput>
GEOM_LABEL: Label for provider /dev/ad0s1d is label/var
&prompt.root; <userinput>glabel label usr /dev/ad0s1f</userinput>
GEOM_LABEL: Label for provider /dev/ad0s1f is label/usr
&prompt.root; <userinput>glabel label tmp /dev/ad0s1e</userinput>
GEOM_LABEL: Label for provider /dev/ad0s1e is label/tmp
&prompt.root; <userinput>glabel label swap /dev/ad0s1b</userinput>
GEOM_LABEL: Label for provider /dev/ad0s1b is label/swap
&prompt.root; <userinput>exit</userinput></screen>

	<para>ϵͳ¼Ó¼ÌÐøÆô¶¯½øÈë¶àÓû§Ä£Ê½¡£ ÔÚÆô¶¯Íê±Ïºó£¬ ±à¼­
	  <filename>/etc/fstab</filename> Óø÷×ԵıêÇ©Ì滻ϳ£¹æµÄÉ豸Ãû¡£
	  ×îÖÕ <filename>/etc/fstab</filename> ¿´ÆðÀ´²î²»¶àÊÇÕâÑùµÄ£º</para>

	<programlisting># Device                Mountpoint      FStype  Options         Dump    Pass#
/dev/label/swap         none            swap    sw              0       0
/dev/label/rootfs       /               ufs     rw              1       1
/dev/label/tmp          /tmp            ufs     rw              2       2
/dev/label/usr          /usr            ufs     rw              2       2
/dev/label/var          /var            ufs     rw              2       2</programlisting>

	<para>ÏÖÔÚ¿ÉÒÔÖØÆôϵͳÁË¡£ Èç¹ûÒ»ÇÐ˳ÀûµÄ»°£¬
	  ϵͳ¿ÉÒÔÕý³£Æô¶¯²¢ÇÒ <command>mount</command> ÃüÁîÏÔʾ£º</para>

	<screen>&prompt.root; <userinput>mount</userinput>
/dev/label/rootfs on / (ufs, local)
devfs on /dev (devfs, local)
/dev/label/tmp on /tmp (ufs, local, soft-updates)
/dev/label/usr on /usr (ufs, local, soft-updates)
/dev/label/var on /var (ufs, local, soft-updates)</screen>
      </example>

      <para>´Ó &os;&nbsp;7.2 ¿ªÊ¼£¬ &man.glabel.8; class
	ÐÂÔöÁËÒ»ÖÖÓÃÓÚ <acronym>UFS</acronym> ÎļþϵͳΨһ±êʶ·û£¬
	<literal>ufsid</literal> µÄ±êÇ©Ö§³Ö¡£
	ÕâЩ±êÇ©¿ÉÒÔÔÚ <filename class="directory">/dev/ufsid</filename>
	Ŀ¼ÖÐÕÒµ½£¬ ËüÃÇ»áÔÚϵͳÒýµ¼Ê±×Ô¶¯´´½¨¡£
	ÔÚ <filename>/etc/fstab</filename> »úÖÆÖУ¬
	Ò²¿ÉÒÔʹÓà <literal>ufsid</literal> ±êÇ©¡£ Äú¿ÉÒÔʹÓÃ
	<command>glabel status</command> ÃüÁîÀ´»ñµÃÓëÎļþϵͳ¶ÔÓ¦µÄ
	<literal>ufsid</literal> ±êÇ©ÁÐ±í£º</para>

      <screen>&prompt.user; <userinput>glabel status</userinput>
                  Name  Status  Components
ufsid/486b6fc38d330916     N/A  ad4s1d
ufsid/486b6fc16926168e     N/A  ad4s1f</screen>

      <para>ÔÚÉÏÃæµÄÀý×ÓÖÐ <devicename>ad4s1d</devicename>
	´ú±íÁË <filename class="directory">/var</filename>
	Îļþϵͳ£¬ ¶ø <devicename>ad4s1f</devicename> Ôò´ú±íÁË
	<filename class="directory">/usr</filename> Îļþϵͳ¡£ Äú¿ÉÒÔʹÓÃÕâЩ
	<literal>ufsid</literal> ÖµÀ´¹ÒÔØËüÃÇ£¬ ÔÚ
	<filename>/etc/fstab</filename> ÖÐÅäÖÃÀàËÆÕâÑù£º</para>

      <programlisting>/dev/ufsid/486b6fc38d330916        /var        ufs        rw        2      2
/dev/ufsid/486b6fc16926168e        /usr        ufs        rw        2      2</programlisting>

      <para>ËùÓаüº¬ÁË <literal>ufsid</literal> µÄ±êÇ©¶¼¿ÉÒÔÓÃÕâÖÖ·½Ê½¹ÒÔØ£¬
	´Ó¶øÏû³ýÁËÐèÒªÊÖ¹¤´´½¨ÓÀ¾ÃÐÔ±êÇ©µÄÂé·³£¬
	¶øÓÖÄܹ»ÌṩÌṩÓëÉ豸ÃûÎ޹صĹÒÔØ·½Ê½µÄ±ãÀû¡£</para>
    </sect2>
  </sect1>

  <sect1 id="geom-gjournal">
    <title>ͨ¹ý GEOM ʵÏÖ UFS ÈÕÖ¾</title>

    <indexterm>
      <primary>GEOM</primary>
    </indexterm>
    <indexterm>
      <primary>ÈÕÖ¾</primary>
    </indexterm>

    <para>Ëæ×Å &os;&nbsp;7.0 µÄ·¢²¼£¬
      ÌṩÁ˳¤ÆÚΪÈËÃÇËùÆÚ´ýµÄÈÕÖ¾¹¦ÄܵÄʵÏÖ¡£ Õâ¸öʵÏÖ²ÉÓÃÁË
      <acronym>GEOM</acronym> ×Óϵͳ£¬ ¿ÉÒÔºÜÈÝÒ×µØʹÓà &man.gjournal.8; ¹¤¾ßÀ´½øÐÐÅäÖá£</para>

    <para>ÈÕÖ¾ÊÇʲô£¿ ÈÕÖ¾µÄ×÷ÓÃÊDZ£´æÎļþϵͳÊÂÎñµÄ¼Ç¼£¬ »»ÑÔÖ®£¬
      Íê³ÉÒ»´ÎÍêÕûµÄ´ÅÅÌдÈë²Ù×÷ËùÐèµÄ±ä¶¯£¬ ÕâЩ¼Ç¼»áÔÚÔªÊý¾ÝÒÔ¼°ÎļþÊý¾ÝдÅÌ֮ǰ£¬
      дÈëµ½´ÅÅÌÖС£ ÕâÖÖÊÂÎñÈÕÖ¾¿ÉÒÔÔÚËæºóÓÃÓÚÖطŲ¢Íê³ÉÎļþϵͳÊÂÎñ£¬
      ÒÔ±ÜÃâÎļþϵͳ³öÏÖ²»Ò»ÖµÄÎÊÌâ¡£</para>

    <para>ÕâÖÖ·½·¨ÊÇÁíÒ»ÖÖ×èÖ¹Îļþϵͳ¶ªÊ§Êý¾Ý²¢·¢Éú²»Ò»Öµķ½·¨¡£ Óë Soft Updates
      ×·×Ù²¢È·±£ÔªÊý¾Ý¸üÐÂ˳ÐòÕâÖÖ·½·¨²»Í¬£¬
      Ëü»áʵ¼ÊµØ½«ÈÕÖ¾±£´æµ½Ö¸¶¨Îª´ËÏîÈÎÎñ±£ÁôµÄ´ÅÅÌ¿Õ¼äÉÏ£¬
      ÔÚijЩÇé¿öÏ¿ÉÈ«²¿´æ·Åµ½ÁíÍâÒ»¿é´ÅÅÌÉÏ¡£</para>

    <para>ÓëÆäËûÎļþϵͳµÄÈÕ־ʵÏÖ²»Í¬£¬
      <command>gjournal</command> ²ÉÓõÄÊÇ»ùÓڿ飬 ¶ø²»ÊÇ×÷ΪÎļþϵͳµÄÒ»²¿·ÖµÄ·½Ê½ -
      ËüÖ»ÊÇ×÷ΪһÖÖ
      <acronym>GEOM</acronym> À©Õ¹ÊµÏÖ¡£</para>

    <para>Èç¹ûÏ£ÍûÆôÓà <command>gjournal</command>£¬
      &os; ÄÚºËÐèÒªÏÂÁÐÑ¡Ïî - ÕâÊÇ &os; 7.0 ÒÔ¼°¸ü¸ß°æ±¾ÏµÍ³ÉϵÄĬÈÏÅäÖãº</para>

    <programlisting>options	UFS_GJOURNAL</programlisting>

    <para>Èç¹ûʹÓÃÈÕÖ¾µÄ¾íÐèÒªÔÚÆô¶¯µÄʱºò±»¹ÒÔØ£¬ »¹Ðè¼ÓÔØ
      <filename>geom_journal.ko</filename> ÄÚºËÄ£¿é£¬
      ½«ÒÔÏÂÕâÐмÓÈë <filename>/boot/loader.conf</filename>£º</para>

    <programlisting>geom_journal_load="YES"</programlisting>

    <para>Õâ¸ö¹¦ÄÜÒ²¿É±»±àÒë½øÒ»¸ö¶¨ÖƵÄÄںˣ¬
      ÐèÔÚÄÚºËÅäÖÃÎļþÖмÓÈëÒÔÏÂÕâÐУº</para>

    <programlisting>options	GEOM_JOURNAL</programlisting>

    <para>ÏÖÔÚ£¬ ¿ÉÒÔΪ¿ÕÏеÄÎļþϵͳ´´½¨ÈÕÖ¾ÁË¡£ ¶ÔÓÚÐÂÔöµÄ <acronym>SCSI</acronym> ´ÅÅÌ
      <devicename>da4</devicename>£¬ ¾ßÌåµÄ²Ù×÷²½ÖèΪ£º</para>

    <screen>&prompt.root; <userinput>gjournal load</userinput>
&prompt.root; <userinput>gjournal label /dev/da4</userinput></screen>

    <para>ÕâÑù£¬ ¾Í»á³öÏÖÒ»¸öÓë
      <devicename>/dev/da4</devicename> É豸½Úµã¶ÔÓ¦µÄ
      <devicename>/dev/da4.journal</devicename> É豸½Úµã¡£
      ½ÓÏÂÀ´£¬ ¿ÉÒÔÔÚÕâ¸öÉ豸ÉϽ¨Á¢Îļþϵͳ£º</para>

    <screen>&prompt.root; <userinput>newfs -O 2 -J /dev/da4.journal</userinput></screen>

    <para>Õâ¸öÃüÁ½¨Á¢Ò»¸ö°üº¬ÈÕÖ¾É豸µÄ
      <acronym>UFS</acronym>2 Îļþϵͳ¡£</para>

    <para>È»ºó¾Í¿ÉÒÔÓà <command>mount</command> ÃüÁîÀ´¹Ò½ÓÉ豸ÁË£º</para>

    <screen>&prompt.root; <userinput>mount /dev/da4.journal <replaceable>/mnt</replaceable></userinput></screen>

    <note>
      <para>µ±´ÅÅÌ°üº¬¶à¸ö slice ʱ£¬ ÿ¸ö slice É϶¼»á½¨Á¢ÈÕÖ¾¡£
	ÀýÈ磬 Èç¹ûÓÐ <devicename>ad4s1</devicename> ºÍ
	<devicename>ad4s2</devicename> ÕâÁ½¸ö slice£¬
	Ôò <command>gjournal</command> »á½¨Á¢
	<devicename>ad4s1.journal</devicename> ºÍ
	<devicename>ad4s2.journal</devicename>¡£</para>
    </note>

    <para>³öÓÚÐÔÄÜ¿¼ÂÇ£¬ ¿ÉÄÜ»áÏ£ÍûÔÚÆäËû´ÅÅÌÉϱ£´æÈÕÖ¾¡£ ¶ÔÓÚÕâÀàÇéÐΣ¬
      Ó¦¸ÃÔÚÆôÓÃÈÕÖ¾µÄÉ豸ºóÃ棬¸ø³öÈÕÖ¾ÌṩÕß»ò´æ´¢É豸¡£ ÔÚôß´æµÄÎļþϵͳÉÏ£¬
      ¿ÉÒÔÓà <command>tunefs</command> À´ÆôÓÃÈÕÖ¾£» ²»¹ý£¬
      ÔÚ³¢ÊÔÐÞ¸ÄÎļþϵͳ֮ǰ£¬ ÄúÓ¦¶ÔÆä½øÐб¸·Ý¡£ ¶àÊýÇé¿öÏ£¬
      Èç¹ûÎÞ·¨´´½¨Êµ¼ÊµÄÈÕÖ¾£¬ <command>gjournal</command> ¾Í»áʧ°Ü£¬ 
      ²¢ÇÒ²»»á·ÀÖ¹ÓÉÓÚ²»µ±Ê¹Óà <command>tunefs</command> ¶øÔì³ÉµÄÊý¾Ý¶ªÊ§¡£</para>

    <para>¶ÔÓÚ &os; ϵͳµÄÆô¶¯´ÅÅÌʹÓÃÈÕÖ¾Ò²ÊÇ¿ÉÄܵġ£
      Çë²ÎÔÄ <ulink
	url="&url.articles.gjournal-desktop;">Implementing UFS Journaling on
	a Desktop PC</ulink> ÒÔ»ñµÃ¸ü¶àÏêϸÐÅÏ¢¡£</para>
  </sect1>
</chapter>