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<chapter id="GEOM">
<chapterinfo>
<authorgroup>
<author>
<firstname>Tom</firstname>
<surname>Rhodes</surname>
<contrib>ÃñÜöôçêå áðü ôïí </contrib>
</author>
</authorgroup>
</chapterinfo>
<title>GEOM: Äéá÷åßñéóç Óõóôïé÷éþí Äßóêùí</title>
<sect1 id="GEOM-synopsis">
<title>Óýíïøç</title>
<indexterm>
<primary>GEOM</primary>
</indexterm>
<indexterm>
<primary>GEOM Disk Framework</primary>
<see>GEOM</see>
</indexterm>
<para>Ôï êåöÜëáéï áõôü êáëýðôåé ôç ÷ñÞóç ôùí äßóêùí êÜôù áðü ôï ðëáßóéï
ëåéôïõñãéþí GEOM óôï &os;. ÐåñéëáìâÜíåé ôá êõñéüôåñá ðñïãñÜììáôá
åëÝã÷ïõ <acronym
role="Redundant Array of Inexpensive Disks">RAID</acronym>
ôùí ïðïßùí ïé ñõèìßóåéò âáóßæïíôáé óôï ðëáßóéï GEOM. Ôï êåöÜëáéï áõôü
äåí áíáëýåé óå âÜèïò ôïí ôñüðï ìå ôïí ïðïßï ôï GEOM ÷åéñßæåôáé Þ åëÝã÷åé
ëåéôïõñãßåò Åéóüäïõ / Åîüäïõ (IO), ôï õðïóýóôçìá ðïõ âñßóêåôáé êÜôù áðü
áõôü, Þ ôïí êþäéêá ôïõ. Ïé ðëçñïöïñßåò áõôÝò ðáñÝ÷ïíôáé áðü ôç óåëßäá
manual ôïõ &man.geom.4; êáèþò êáé áðü ôéò áíáöïñÝò ðïõ ðåñéÝ÷åé óå Üëëåò
ó÷åôéêÝò óåëßäåò. Åðßóçò ôï êåöÜëáéï áõôü äåí áðïôåëåß êáèïñéóôéêü
ïäçãü ãéá üëåò ôéò ñõèìßóåéò ôïõ <acronym>RAID</acronym>.
Èá óõæçôçèïýí ìüíï ïé êáôáóôÜóåéò ëåéôïõñãßáò ôïõ
<acronym>RAID</acronym> ðïõ õðïóôçñßæïíôáé áðü ôï GEOM.</para>
<para>Áöïý äéáâÜóåôå áõôü ôï êåöÜëáéï, èá îÝñåôå:</para>
<itemizedlist>
<listitem>
<para>Ôï åßäïò ôçò õðïóôÞñéîçò <acronym>RAID</acronym> ðïõ åßíáé
äéáèÝóéìï ìÝóù ôïõ GEOM.</para>
</listitem>
<listitem>
<para>Ðùò íá ÷ñçóéìïðïéÞóåôå ôá âáóéêÜ âïçèçôéêÜ ðñïãñÜììáôá ãéá ôçí
ñýèìéóç, óõíôÞñçóç êáé äéá÷åßñéóç ôùí äéáöüñùí åðéðÝäùí <acronym>
RAID</acronym>.</para>
</listitem>
<listitem>
<para>Ðùò íá äçìéïõñãÞóåôå mirror Þ stripe, íá êñõðôïãñáöÞóåôå, êáé íá
óõíäÝóåôå äßóêïõò ìå ôï GEOM, ìÝóù ìéáò áðïìáêñõóìÝíçò
óýíäåóçò.</para>
</listitem>
<listitem>
<para>Ðùò íá áíôéìåôùðßóåôå ðñïâëÞìáôá äßóêùí ðïõ ÷ñçóéìïðïéïýí ôï
ðëáßóéï ëåéôïõñãéþí GEOM.</para>
</listitem>
</itemizedlist>
<para>Ðñéí äéáâÜóåôå áõôü ôï êåöÜëáéï, èá ðñÝðåé:</para>
<itemizedlist>
<listitem>
<para>Íá êáôáíïåßôå ðùò ìåôá÷åéñßæåôáé ôï &os; ôéò óõóêåõÝò äßóêùí
(<xref linkend="disks"/>).</para>
</listitem>
<listitem>
<para>Íá ãíùñßæåôå ðùò èá ñõèìßóåôå êáé èá åãêáôáóôÞóåôå Ýíá íÝï
ðõñÞíá óôï &os; (<xref linkend="kernelconfig"/>).</para>
</listitem>
</itemizedlist>
</sect1>
<sect1 id="GEOM-intro">
<title>ÅéóáãùãÞ óôï GEOM</title>
<para>Ôï GEOM åðéôñÝðåé ôçí ðñüóâáóç êáé ôïí Ýëåã÷ï óå êëÜóåéò —
üðùò ôçí ÊåíôñéêÞ ÅããñáöÞ Åêêßíçóçò (Master Boot Record), ôá
<acronym>BSD</acronym> labels, ê.á. — ìÝóù ôçò ÷ñÞóçò ðáñï÷Ýùí,
Þ ìÝóù åéäéêþí áñ÷åßùí óôïí êáôÜëïãï
<filename class="directory">/dev</filename>. Ôï GEOM õðïóôçñßæåé
äéÜöïñåò äéáôÜîåéò <acronym>RAID</acronym> êáé ðáñÝ÷åé äéÜöáíç
ðñüóâáóç óôï ëåéôïõñãéêü óýóôçìá êáé ôá âïçèçôéêÜ ôïõ
ðñïãñÜììáôá.</para>
</sect1>
<sect1 id="GEOM-striping">
<sect1info>
<authorgroup>
<author>
<firstname>Tom</firstname>
<surname>Rhodes</surname>
<contrib>ÃñÜöçêå áðü ôïõò </contrib>
</author>
<author>
<firstname>Murray</firstname>
<surname>Stokely</surname>
</author>
</authorgroup>
</sect1info>
<title>RAID0 - Striping</title>
<indexterm>
<primary>GEOM</primary>
</indexterm>
<indexterm>
<primary>Striping</primary>
</indexterm>
<para>Ôï striping åßíáé ìéá ìÝèïäïò ðïõ óõíäõÜæåé äéáöïñåôéêïýò öõóéêïýò
äßóêïõò óå Ýíá ìïíáäéêü ëïãéêü ôüìï. Óå ðïëëÝò ðåñéðôþóåéò, áõôü
ãßíåôáé ìå ôçí âïÞèåéá åîåéäéêåõìÝíïõ õëéêïý (åëåãêôþí). Ôï õðïóýóôçìá
äßóêùí GEOM ðáñÝ÷åé õðïóôÞñéîç ìÝóù ëïãéóìéêïý ãéá ôç äéÜôáîç
<acronym>RAID</acronym>0, ç ïðïßá åßíáé ãíùóôÞ êáé ùò striping.</para>
<para>Óå Ýíá óýóôçìá <acronym>RAID</acronym>0, ôá äåäïìÝíá ÷ùñßæïíôáé óå
blocks ôá ïðïßá ãñÜöïíôáé ôìçìáôéêÜ óå üëïõò ôïõò äßóêïõò ðïõ áðïôåëïýí
ôç óõóôïé÷ßá. Áíôß íá ÷ñåéÜæåôáé íá ðåñéìÝíåôå ôï óýóôçìá íá ãñÜøåé
256k äåäïìÝíùí óå Ýíá äßóêï, Ýíá óýóôçìá <acronym>RAID</acronym>0 ìðïñåß
íá ãñÜøåé ôáõôü÷ñïíá 64k óå êáèÝíá áðü ôïõò ôÝóóåñéò äßóêïõò ìéáò
óõóôïé÷ßáò, ðñïóöÝñïíôáò Ýôóé åîáéñåôéêÞ áðüäïóç åéóüäïõ/åîüäïõ (I/O).
Ç áðüäïóç áõôÞ ìðïñåß íá áõîçèåß ðåñéóóüôåñï, ìå ôç ÷ñÞóç ðïëëáðëþí
åëåãêôþí äßóêùí.</para>
<para>ÊÜèå äßóêïò óå Ýíá stripe <acronym>RAID</acronym>0 ðñÝðåé íá åßíáé
ôïõ ßäéïõ ìåãÝèïõò, êáèþò ïé áéôÞóåéò I/O ìïéñÜæïíôáé üóï áöïñÜ ôçí
áíÜãíùóç êáé åããñáöÞ, óå ðïëëïýò ðáñÜëëçëïõò äßóêïõò.</para>
<mediaobject>
<imageobject>
<imagedata fileref="geom/striping" align="center"/>
</imageobject>
<textobject>
<phrase>ÄéÜãñáììá Disk Striping</phrase>
</textobject>
</mediaobject>
<procedure>
<title>Äçìéïõñãßá Stripe áðü ìç-ÄéáìïñöùìÝíïõò ATA Äßóêïõò</title>
<step>
<para>Öïñôþóôå ôï Üñèñùìá <filename>geom_stripe.ko</filename>:</para>
<screen>&prompt.root; <userinput>kldload geom_stripe</userinput></screen>
</step>
<step>
<para>Åîáóöáëßóôå üôé õðÜñ÷åé êáôÜëëçëï óçìåßï ðñïóÜñôçóçò. Áí ï
ôüìïò ðñüêåéôáé íá ãßíåé êáôÜôìçóç root, ðñïóáñôÞóôå ôïí
ðñïóùñéíÜ óå êÜðïéï Üëëï óçìåßï ðñïóÜñôçóçò, üðùò ôï
<filename class="directory">/mnt</filename>:</para>
<screen>&prompt.root; <userinput>mkdir /mnt</userinput></screen>
</step>
<step>
<para>Êáèïñßóôå ôá ïíüìáôá ôùí óõóêåõþí ãéá ôïõò äßóêïõò ðïõ ðñüêåéôáé
íá ãßíïõí stripe, êáé äçìéïõñãÞóôå ôç íÝá óõóêåõÞ stripe. Ãéá
ðáñÜäåéãìá, ãéá íá äçìéïõñãÞóåôå Ýíá stripe áðü äýï
á÷ñçóéìïðïßçôïõò êáé ÷ùñßò êáôáôìÞóåéò äßóêïõò
<acronym>ATA</acronym>, üðùò ð.÷. ôïõò
<filename>/dev/ad2</filename> êáé
<filename>/dev/ad3</filename>:</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>ÃñÜøôå Ýíá ôõðïðïéçìÝíï label (ðßíáêá êáôáôìÞóåùí) óôï íÝï
ôüìï, êáé åãêáôáóôÞóôå ôïí ðñïåðéëåãìÝíï êþäéêá åêêßíçóçò
(bootstrap):</para>
<screen>&prompt.root; <userinput>bsdlabel -wB /dev/stripe/st0</userinput></screen>
</step>
<step>
<para>Ç äéáäéêáóßá áõôÞ èá äçìéïõñãÞóåé ôç óõóêåõÞ
<devicename>st0</devicename>, êáèþò êáé äýï áêüìá óõóêåõÝò óôïí
êáôÜëïãï <filename class="directory">/dev/stripe</filename>.
Ïé óõóêåõÝò áõôÝò èá ïíïìÜæïíôáé <devicename>st0a</devicename> êáé
<devicename>st0c</devicename>. Óôï óçìåßï áõôü, ìðïñåßôå ðëÝïí íá
äçìéïõñãÞóåôå óýóôçìá áñ÷åßùí óôç óõóêåõÞ
<devicename>st0a</devicename> ÷ñçóéìïðïéþíôáò ôï âïçèçôéêü ðñüãñáììá
<command>newfs</command>:</para>
<screen>&prompt.root; <userinput>newfs -U /dev/stripe/st0a</userinput></screen>
<para>Èá äåßôå ìéá ìåãÜëç óåéñÜ áñéèìþí íá ðåñíÜ ãñÞãïñá áðü ôçí
ïèüíç óáò, êáé ìåôÜ áðü ëßãá äåõôåñüëåðôá ç äéáäéêáóßá èá Ý÷åé
ïëïêëçñùèåß. Ï ôüìïò èá Ý÷åé äçìéïõñãçèåß êáé èá åßíáé Ýôïéìïò
ãéá ðñïóÜñôçóç.</para>
</step>
</procedure>
<para>Ãéá íá ðñïóáñôÞóåôå ÷åéñïêßíçôá ôï stripe ðïõ äçìéïõñãÞóáôå:</para>
<screen>&prompt.root; <userinput>mount /dev/stripe/st0a /mnt</userinput></screen>
<para>Ãéá íá ãßíåôáé áõôüìáôá ç ðñïóÜñôçóç áõôïý ôïõ óõóôÞìáôïò áñ÷åßùí
êáôÜ ôçí äéáäéêáóßá åêêßíçóçò, ôïðïèåôÞóôå ôéò ðëçñïöïñßåò ôïõ ôüìïõ óôï
áñ÷åßï <filename>/etc/fstab</filename>. Ãéá ôï óêïðü áõôü,
äçìéïõñãïýìå Ýíá ìüíéìï óçìåßï ðñïóÜñôçóçò, ôï <filename
class="directory">stripe</filename>:</para>
<screen>&prompt.root; <userinput>mkdir /stripe</userinput>
&prompt.root; <userinput>echo "/dev/stripe/st0a /stripe ufs rw 2 2" \</userinput>
<userinput>>> /etc/fstab</userinput></screen>
<para>Ôï Üñèñùìá <filename>geom_stripe.ko</filename> èá ðñÝðåé íá
öïñôþíåôáé áõôüìáôá êáôÜ ôçí åêêßíçóç ôïõ óõóôÞìáôïò.
ÅêôåëÝóôå ôçí ðáñáêÜôù åíôïëÞ, ãéá íá ðñïóèÝóåôå ôçí êáôÜëëçëç ñýèìéóç
óôï <filename>/boot/loader.conf</filename>:</para>
<screen>&prompt.root; <userinput>echo 'geom_stripe_load="YES"' >> /boot/loader.conf</userinput></screen>
</sect1>
<sect1 id="GEOM-mirror">
<title>RAID1 - Mirroring</title>
<indexterm>
<primary>GEOM</primary>
</indexterm>
<indexterm>
<primary>Disk Mirroring</primary>
</indexterm>
<para>Ôï mirroring (êáèñåöôéóìüò) åßíáé ìéá ôå÷íïëïãßá ðïõ
÷ñçóéìïðïéåßôáé áðü ðïëëÝò åôáéñßåò êáé ïéêéáêïýò ÷ñÞóôåò ãéá íá
áóöáëßóïõí ôá äåäïìÝíá ôïõò ÷ùñßò äéáêïðÝò. Óå ìéá äéÜôáîç mirror,
ï äßóêïò Â åßíáé áðëþò Ýíá ðëÞñåò áíôßãñáöï ôïõ äßóêïõ Á. ¹ ìðïñåß
ïé äßóêïé Ã+Ä íá åßíáé áíôßãñáöá ôùí äßóêùí A+B. ¶ó÷åôá ìå ôçí
áêñéâÞ äéÜôáîç ôùí äßóêùí, ôï óçìáíôéêü åßíáé üôé ïé ðëçñïöïñßåò åíüò
äßóêïõ Þ ìéáò êáôÜôìçóçò áíôéãñÜöïíôáé óå Üëëïõò. Ïé ðëçñïöïñßåò
áõôÝò ìðïñåß áñãüôåñá íá áðïêáôáóôáèïýí ìå åýêïëï ôñüðï, Þ íá
áíôéãñáöïýí ÷ùñßò íá ðñïêëçèåß äéáêïðÞ óôéò õðçñåóßåò ôïõ ìç÷áíÞìáôïò
Þ óôçí ðñüóâáóç ôùí äåäïìÝíùí. Ìðïñïýí áêüìá êáé íá ìåôáöåñèïýí êáé
íá öõëá÷èïýí óå Üëëï, áóöáëÝò ìÝñïò.</para>
<para>Ãéá íá îåêéíÞóåôå, âåâáéùèåßôå üôé ôï óýóôçìá óáò Ý÷åé äýï óêëçñïýò
äßóêïõò ßäéïõ ìåãÝèïõò. Óôá ðáñáäåßãìáôá ìáò èåùñïýìå üôé ïé äßóêïé
åßíáé ôýðïõ <acronym>SCSI</acronym> (áðåõèåßáò ðñüóâáóçò,
&man.da.4;).</para>
<sect2>
<title>Mirroring óôïõò Âáóéêïýò Äßóêïõò</title>
<para>ÕðïèÝôïíôáò üôé ôï &os; Ý÷åé åãêáôáóôáèåß óôïí ðñþôï äßóêï
<devicename>da0</devicename>, èá ðñÝðåé íá ñõèìßóåôå ôï
&man.gmirror.8; íá áðïèçêåýóåé åêåß ôá âáóéêÜ äåäïìÝíá ôïõ.</para>
<para>Ðñéí äçìéïõñãÞóåôå ôï mirror, åíåñãïðïéÞóôå ôçí äõíáôüôçôá
åìöÜíéóçò ðåñéóóüôåñùí ëåðôïìåñåéþí (ðïõ ìðïñåß íá óáò âïçèÞóïõí óå
ðåñßðôùóç ðñïâëÞìáôïò) êáé åðéôñÝøôå ôçí áðåõèåßáò ðñüóâáóç óôç
óõóêåõÞ äßóêïõ. Ãéá ôï óêïðü áõôü èÝóôå ôç ìåôáâëçôÞ
<varname>kern.geom.debugflags</varname> ôïõ &man.sysctl.8;
óôçí ðáñáêÜôù ôéìÞ:</para>
<screen>&prompt.root; <userinput>sysctl kern.geom.debugflags=17</userinput></screen>
<para>Ìðïñåßôå ôþñá íá äçìéïõñãÞóåôå ôï mirror. ÎåêéíÞóôå ôç
äéáäéêáóßá áðïèçêåýïíôáò ôá ìåôá-äåäïìÝíá (meta-data) óôïí âáóéêü
äßóêï, äçìéïõñãþíôáò ïõóéáóôéêÜ ôç óõóêåõÞ
<filename class="devicefile">/dev/mirror/gm</filename>.
×ñçóéìïðïéÞóôå ôçí ðáñáêÜôù åíôïëÞ:</para>
<warning>
<para>Ç äçìéïõñãßá mirror óôï äßóêï åêêßíçóçò ìðïñåß íá Ý÷åé ùò
áðïôÝëåóìá ôçí áðþëåéá äåäïìÝíùí, áí ï ôåëåõôáßïò ôïìÝáò ôïõ äßóêïõ
Ý÷åé Þäç ÷ñçóéìïðïéçèåß. Ç ðéèáíüôçôá áõôÞ åßíáé ðïëý ìéêñüôåñç
áí ôï mirror äçìéïõñãçèåß áìÝóùò ìåôÜ áðü ìéá íÝá åãêáôÜóôáóç ôïõ
&os;. Ç ðáñáêÜôù äéáäéêáóßá åßíáé åðßóçò áóýìâáôç ìå ôéò
ðñïåðéëåãìÝíåò ñõèìßóåéò åãêáôÜóôáóçò ôïõ
&os; 9.<replaceable>X</replaceable> óôéò ïðïßåò
÷ñçóéìïðïéåßôáé ôï óýóôçìá êáôáôìÞóåùí <acronym>GPT</acronym>.
To GEOM êáôáóôñÝöåé ôá ìåôáäåäïìÝíá ôïõ <acronym>GPT</acronym>,
êáé èá ðñïêáëÝóåé áðþëåéá äåäïìÝíùí êáé ðéèáíÞ áäõíáìßá åêêßíçóçò
ôïõ óõóôÞìáôïò.</para>
</warning>
<screen>&prompt.root; <userinput>gmirror label -vb round-robin gm0 /dev/da0</userinput></screen>
<para>Ôï óýóôçìá èá áíôáðïêñéèåß ìå ôï ðáñáêÜôù ìÞíõìá:</para>
<screen>Metadata value stored on /dev/da0.
Done.</screen>
<para>Áñ÷éêïðïéÞóôå ôï GEOM. Ç ðáñáêÜôù åíôïëÞ èá öïñôþóåé ôï Üñèñùìá
<filename>/boot/kernel/geom_mirror.ko</filename> óôïí ðõñÞíá:</para>
<screen>&prompt.root; <userinput>gmirror load</userinput></screen>
<note>
<para>Ìå ôçí åðéôõ÷Þ åêôÝëåóç áõôÞò ôçò åíôïëÞò, äçìéïõñãåßôáé ç
óõóêåõÞ <devicename>gm0</devicename> ìÝóá óôïí êáôÜëïãï
<filename class="directory">/dev/mirror</filename>.</para>
</note>
<para>ÅíåñãïðïéÞóôå ôï öüñôùìá ôïõ áñèñþìáôïò
<filename>geom_mirror.ko</filename> êáôÜ ôçí åêêßíçóç ôïõ
óõóôÞìáôïò:</para>
<screen>&prompt.root; <userinput>echo 'geom_mirror_load="YES"' >> /boot/loader.conf</userinput></screen>
<para>Åðåîåñãáóôåßôå ôï áñ÷åßï <filename>/etc/fstab</filename>,
áíôéêáèéóôþíôáò ôéò áíáöïñÝò óôéò ðáëéÝò óõóêåõÝò
<devicename>da0</devicename> ìå ôéò áíôßóôïé÷åò êáéíïýñéåò
<devicename>gm0</devicename> ðïõ áíôéðñïóùðåýïõí ôï mirror.</para>
<note>
<para>Áí ÷ñçóéìïðïéåßôå ôï &man.vi.1;, ìðïñåßôå íá áêïëïõèÞóåôå ôá
ðáñáêÜôù âÞìáôá ãéá íá ïëïêëçñþóåôå åýêïëá áõôÞ ôç
äéáäéêáóßá:</para>
<screen>&prompt.root; <userinput>vi /etc/fstab</userinput></screen>
<para>Óôï &man.vi.1;, êñáôÞóôå áíôßãñáöï áóöáëåßáò ôïõ ôñÝ÷ïíôïò
áñ÷åßïõ <filename>fstab</filename> ðëçêôñïëïãþíôáò
<userinput>:w /etc/fstab.bak</userinput>. ¸ðåéôá áíôéêáôáóôÞóôå
üëåò ôéò áíáöïñÝò óôéò ðáëéÝò óõóêåõÝò <devicename>da0</devicename>
ìå ôéò íÝåò <devicename>gm0</devicename> ãñÜöïíôáò
<userinput>:%s/da/mirror\/gm/g</userinput>.</para>
</note>
<para>Ôï <filename>fstab</filename> ðïõ èá ðñïêýøåé, èá ìïéÜæåé ìå
ôï ðáñáêÜôù. Äåí Ý÷åé óçìáóßá áí ïé äßóêïé Þôáí áñ÷éêÜ
<acronym>SCSI</acronym> Þ <acronym>ATA</acronym>, ç óõóêåõÞ
<acronym>RAID</acronym> èá Ý÷åé ðÜíôá ôï üíïìá
<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>ÅðáíåêêéíÞóôå ôï óýóôçìá:</para>
<screen>&prompt.root; <userinput>shutdown -r now</userinput></screen>
<para>ÊáôÜ ôçí åêêßíçóç ôïõ óõóôÞìáôïò, èá ðñÝðåé ðëÝïí íá
÷ñçóéìïðïéåßôáé ç óõóêåõÞ <devicename>gm0</devicename> áíôß ãéá ôçí
<devicename>da0</devicename>. ÌåôÜ ôï ôÝëïò ôçò åêêßíçóçò, ìðïñåßôå
íá åëÝãîåôå üôé üëá ëåéôïõñãïýí óùóôÜ, åîåôÜæïíôáò ôçí Ýîïäï ôçò
åíôïëÞò <command>mount</command>:</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>Ç Ýîïäïò öáßíåôáé óùóôÞ, üðùò áíáìåíüôáí. ÔåëéêÜ, ãéá íá
îåêéíÞóåé ï óõã÷ñïíéóìüò, åéóÜãåôå êáé ôçí óõóêåõÞ
<devicename>da1</devicename> óôï mirror, ÷ñçóéìïðïéþíôáò ôçí
áêüëïõèç åíôïëÞ:</para>
<screen>&prompt.root; <userinput>gmirror insert gm0 /dev/da1</userinput></screen>
<para>ÊáôÜ ôç äéÜñêåéá ôïõ óõã÷ñïíéóìïý ôïõ mirror, ìðïñåßôå íá äåßôå
ôçí ðñüïäï ôçò äéáäéêáóßáò ìå ôçí ðáñáêÜôù åíôïëÞ:</para>
<screen>&prompt.root; <userinput>gmirror status</userinput></screen>
<para>ÌåôÜ ôï ôÝëïò ôçò äüìçóçò ôïõ mirror, êáé áöïý Ý÷ïõí óõã÷ñïíéóôåß
üëá ôá äåäïìÝíá, ç Ýîïäïò ôçò ðáñáðÜíù åíôïëÞò èá ìïéÜæåé ìå ôçí
áêüëïõèç:</para>
<screen> Name Status Components
mirror/gm0 COMPLETE da0
da1</screen>
<para>Áí õðÜñ÷ïõí ðñïâëÞìáôá, Þ áí ôï mirror âñßóêåôáé áêüìá óôç
äéáäéêáóßá óõã÷ñïíéóìïý, ôï ðáñÜäåéãìá èá äåß÷íåé
<literal>DEGRADED</literal> áíôß ãéá
<literal>COMPLETE</literal>.</para>
</sect2>
<sect2>
<title>Áíôéìåôþðéóç ÐñïâëçìÜôùí</title>
<sect3>
<title>Ôï óýóôçìá áñíåßôáé íá îåêéíÞóåé</title>
<para>Áí ôï óýóôçìá óáò óôáìáôÜåé óå ìéá ðñïôñïðÞ ðïõ ìïéÜæåé ìå ôçí
ðáñáêÜôù:</para>
<programlisting>ffs_mountroot: can't find rootvp
Root mount failed: 6
mountroot></programlisting>
<para>ÅðáíåêêéíÞóôå ôï óýóôçìá óáò ìÝóù ôïõ äéáêüðôç ôñïöïäïóßáò Þ
ôïõ ðëÞêôñïõ reset. Óôï ìåíïý åêêßíçóçò, åðéëÝîôå ôï (6). Ìå ôïí
ôñüðï áõôü èá âñåèåßôå óôçí ðñïôñïðÞ ôïõ &man.loader.8;. Öïñôþóôå
÷åéñïêßíçôá ôï Üñèñùìá óôïí ðõñÞíá:</para>
<screen>OK? <userinput>load geom_mirror</userinput>
OK? <userinput>boot</userinput></screen>
<para>Áí ôï ðáñáðÜíù ëåéôïõñãÞóåé, ôüôå ãéá êÜðïéï ëüãï ôï Üñèñùìá
äåí öïñôþèçêå óùóôÜ. ÅëÝãîôå áí åßíáé óùóôÞ ç ó÷åôéêÞ êáôá÷þñéóç
óôï áñ÷åßï <filename>/boot/loader.conf</filename>. Áí ôï ðñüâëçìá
ðáñáìÝíåé, ðñïóèÝóôå ôç ãñáììÞ:</para>
<programlisting>options GEOM_MIRROR</programlisting>
<para>óôï áñ÷åßï ñõèìßóåùí ôïõ ðõñÞíá óáò, áíáäçìéïõñãÞóôå êáé
åðáíåãêáôáóôÞóôå ôïí ðõñÞíá óáò. Ôï ðñüâëçìá óáò èá ðñÝðåé íá
äéïñèùèåß.</para>
</sect3>
</sect2>
<sect2>
<title>ÅðáíáöïñÜ ÌåôÜ áðü Áðïôõ÷ßá Äßóêïõ</title>
<para>Ôï åêðëçêôéêü ìå ôï mirroring åßíáé üôé üôáí Ýíáò óêëçñüò äßóêïò
÷áëÜóåé, ìðïñåßôå íá ôïí áíôéêáôáóôÞóåôå ÷ùñßò íá ÷Üóåôå êáèüëïõ
äåäïìÝíá.</para>
<para>ÕðïèÝôïíôáò üôé ÷ñçóéìïðïéïýìå ôéò ñõèìßóåéò
<acronym>RAID</acronym>1 ðïõ äåßîáìå ðñïçãïõìÝíùò, áò èåùñÞóïõìå üôé
÷Üëáóå ï äßóêïò <devicename>da1</devicename> êáé ðñÝðåé íá
áíôéêáôáóôáèåß. Ãéá íá ôïí áíôéêáôáóôÞóåôå, âñåßôå ðïéïò äßóêïò åßíáé
êáé áðåíåñãïðïéÞóôå ôï óýóôçìá. Óôï óçìåßï áõôü, ìðïñåßôå ðëÝïí íá
áíôáëëÜîåôå ôï äßóêï ìå Ýíá íÝï êáé íá åíåñãïðïéÞóåôå îáíÜ ôï
óýóôçìá. ÌåôÜ ôçí åðáíåíåñãïðïßçóç ôïõ óõóôÞìáôïò, ìðïñåßôå íá
÷ñçóéìïðïéÞóåôå ôéò ðáñáêÜôù åíôïëÝò ãéá íá èÝóåôå óå ëåéôïõñãßá ôï
íÝï äßóêï:</para>
<screen>&prompt.root; <userinput>gmirror forget gm0</userinput></screen>
<screen>&prompt.root; <userinput>gmirror insert gm0 /dev/da1</userinput></screen>
<para>×ñçóéìïðïéÞóôå ôçí åíôïëÞ <command>gmirror</command>
<option>status</option> ãéá íá ðáñáêïëïõèåßôå ôç äéáäéêáóßá ôïõ
óõã÷ñïíéóìïý. Åßíáé óôá áëÞèåéá ôüóï áðëü.</para>
</sect2>
</sect1>
<sect1 id="GEOM-raid3">
<sect1info>
<authorgroup>
<author>
<firstname>Mark</firstname>
<surname>Gladman</surname>
<contrib>ÃñÜöçêå áðü </contrib>
</author>
<author>
<firstname>Daniel</firstname>
<surname>Gerzo</surname>
</author>
</authorgroup>
<authorgroup>
<author>
<firstname>Tom</firstname>
<surname>Rhodes</surname>
<contrib>ÂáóéóìÝíï óôçí ôåêìçñßùóç ôùí </contrib>
</author>
<author>
<firstname>Murray</firstname>
<surname>Stokely</surname>
</author>
</authorgroup>
</sect1info>
<title><acronym>RAID</acronym>3 - Striping óå Åðßðåäï Byte ìå ÁöïóéùìÝíï
Parity</title>
<indexterm>
<primary>GEOM</primary>
</indexterm>
<indexterm>
<primary>RAID3</primary>
</indexterm>
<para>Ôï <acronym>RAID</acronym>3 åßíáé ìéá ìÝèïäïò ðïõ óõíäõÜæåé
áñêåôïýò äéáöïñåôéêïýò óêëçñïýò äßóêïõò óå Ýíá ôüìï ìå Ýíá äßóêï
áöïóéùìÝíï óôçí éóïôéìßá (parity). Óå Ýíá óýóôçìá
<acronym>RAID</acronym>3, ôá äåäïìÝíá ÷ùñßæïíôáé óå Ýíá áñéèìü áðü
bytes ðïõ åããñÜöïíôáé óå üëïõò ôïõò äßóêïõò ôçò óõóôïé÷ßáò åêôüò áðü
Ýíá ðïõ ÷ñçóéìïðïéåßôáé áðïêëåéóôéêÜ ùò äßóêïò éóïôéìßáò. Áõôü
óçìáßíåé üôé ãéá íá äéáâÜóïõìå 1024KB áðü ìéá õëïðïßçóç ôïõ
<acronym>RAID</acronym>3 èá ðñÝðåé íá ðñïóðåëÜóïõìå üëïõò ôïõò
äßóêïõò ôçò óõóôïé÷ßáò. Ç áðüäïóç áõîÜíåôáé ìå ôç ÷ñÞóç ÷ùñéóôþí
åëåãêôþí óêëçñþí äßóêùí. Ç óõóôïé÷ßá <acronym>RAID</acronym>3
ðñïóöÝñåé áíï÷Þ óå âëÜâç åíüò äßóêïõ åíüò ðáñÝ÷åé ÷ùñçôéêüôçôá
1 - 1/n öïñÝò ôç ÷ùñçôéêüôçôá üëùí ôùí äßóêùí ôçò óõóôïé÷ßáò, üðïõ
n åßíáé ôï ðëÞèïò ôùí äßóêùí ðïõ ôçí áðáñôßæïõí. Áõôïý ôïõ åßäïõò
ïé óõóôïé÷ßåò åßíáé êáôÜëëçëåò ãéá áðïèÞêåõóç ìåãÜëùí áñ÷åßùí, ãéá
ðáñÜäåéãìá áñ÷åßùí ðïëõìÝóùí.</para>
<para>×ñåéÜæïíôáé ôïõëÜ÷éóôïí 3 öõóéêïß óêëçñïß äßóêïé ãéá ôç äçìéïõñãßá
ìéá óõóôïé÷ßáò <acronym>RAID</acronym>3. ÊÜèå äßóêïò èá ðñÝðåé íá
åßíáé ôï ßäéï ìÝãåèïò êáèþò ïé áéôÞóåéò É/Ï (åéóüäïõ/åîüäïõ)
åíáëëÜóóïíôáé þóôå íá ãßíåôáé åããñáöÞ êáé áíÜãíùóç óå ðïëëáðëïýò äßóêïõò
ðáñÜëëçëá. Åðßóçò, åîáéôßáò ôçò öýóçò ôïõ <acronym>RAID</acronym>3,
ï áñéèìüò ôùí äßóêùí ðñÝðåé íá åßíáé 3, 5, 9, 17 êëð. (2^n+1).</para>
<sect2>
<title>Äçìéïõñãßá Óõóôïé÷ßáò <acronym>RAID</acronym>3</title>
<para>Óôï &os;, ç õðïóôÞñéîç ãéá <acronym>RAID</acronym>3 õëïðïéåßôáé
ìÝóù ôçò êëÜóçò &man.graid3.8; ôïõ <acronym>GEOM</acronym>.
Ç äçìéïõñãßá ìéáò óõóôïé÷ßáò <acronym>RAID</acronym>3 óôï &os; áðáéôåß
ôá ðáñáêÜôù âÞìáôá.</para>
<note>
<para>Áí êáé åßíáé èåùñçôéêÜ äõíáôü íá öôéÜîåôå ìéá åêêéíÞóéìç
óõóôïé÷ßá <acronym>RAID</acronym>3 óôï &os;, äåí óõíßóôáôáé êáèþò
ðñüêåéôáé ãéá áóõíÞèéóôç ëåéôïõñãßá.</para>
</note>
<procedure>
<step>
<para>Áñ÷éêÜ, öïñôþóôå ôï <filename>geom_rai3.ko</filename>
Üñèñùìá ôïõ ðõñÞíá ìÝóù ôçò áêüëïõèçò åíôïëÞò:</para>
<screen>&prompt.root; <userinput>graid3 load</userinput></screen>
<para>ÅíáëëáêôéêÜ, åßíáé äõíáôüí íá öïñôþóåôå ôï Üñèñùìá
÷åéñïêßíçôá:</para>
<screen>&prompt.root; <userinput>kldload geom_raid3.ko</userinput></screen>
</step>
<step>
<para>Åîáóöáëßóôå üôé õðÜñ÷åé êáôÜëëçëï óçìåßï ðñïóÜñôçóçò, Þ
äçìéïõñãÞóôå Ýíá êáéíïýñéï:</para>
<screen>&prompt.root; <userinput>mkdir <replaceable>/multimedia</replaceable></userinput></screen>
</step>
<step>
<para>Ðñïóäéïñßóôå ôá ïíüìáôá óõóêåõþí ôùí äßóêùí ðïõ èá ðñïóôåèïýí
óôç óõóôïé÷ßá êáé äçìéïõñãÞóôå ôç íÝá óõóêåõÞ
<acronym>RAID</acronym>3. Óôï ðáñÜäåéãìá ìáò ÷ñçóéìïðïéïýìå
ôñåéò ïäçãïýò <acronym>ATA</acronym> ïé ïðïßïé äåí ðåñéÝ÷ïõí
êáôáôìÞóåéò:
<devicename><replaceable>ada1</replaceable></devicename> êáé
<devicename><replaceable>ada2</replaceable></devicename> ãéá ôá
äåäïìÝíá êáé
<devicename><replaceable>ada3</replaceable></devicename> ãéá ôï
parity.</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>ÄçìéïõñãÞóôå êáôáôìÞóåéò óôç íÝá óõóêåõÞ
<devicename>gr0</devicename> êáé äéáìïñöþóôå ôçí ìå óýóôçìá
áñ÷åßùí UFS:</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>Èá äåßôå ìåãÜëï ðëÞèïò áñéèìþí íá ðåñíÜåé áðü ôçí ïèüíç óáò
êáé ìåôÜ áðü ëßãï ç äéáäéêáóßá èá ïëïêëçñùèåß. Ï ôüìïò Ý÷åé
ðëÝïí äçìéïõñãçèåß êáé åßíáé Ýôïéìïò íá ðñïóáñôçèåß.</para>
</step>
<step>
<para>Ôï ôåëåõôáßï âÞìá åßíáé ç ðñïóÜñôçóç ôïõ óõóôÞìáôïò
áñ÷åßùí:</para>
<screen>&prompt.root; <userinput>mount /dev/raid3/gr0p1 /multimedia</userinput></screen>
<para>Ç óõóôïé÷ßá <acronym>RAID</acronym>3 åßíáé ôþñá Ýôïéìç ðñïò
÷ñÞóç.</para>
</step>
</procedure>
<para>Èá ÷ñåéáóôåß íá êÜíåôå åðéðëÝïí ñõèìßóåéò þóôå ç óõóôïé÷ßá íá
åßíáé Üìåóá äéáèÝóéìç ìåôÜ áðü êÜèå åêêßíçóç ôïõ õðïëïãéóôÞ
óáò.</para>
<procedure>
<step>
<para>Ôï Üñèñùìá <filename>geom_raid3.ko</filename> èá ðñÝðåé íá
öïñôþíåôáé ðñéí ôçí ðñïóÜñôçóç ôçò óõóôïé÷ßáò. Ãéá íá öïñôþíåôáé
áõôüìáôá êáôÜ ôçí åêêßíçóç ôïõ óõóôÞìáôïò, ðñïóèÝóôå ôçí ðáñáêÜôù
ãñáììÞ óôï <filename>/boot/loader.conf</filename>:</para>
<programlisting>geom_raid3_load="YES"</programlisting>
</step>
<step>
<para>Èá ðñÝðåé íá ðñïóèÝóåôå ôéò ðáñáêÜôù ðëçñïöïñßåò ó÷åôéêÜ
ìå ôïí ôüìï óôï áñ÷åßï <filename>/etc/fstab</filename> þóôå ç
ðñïóÜñôçóç ôïõ óõóôÞìáôïò áñ÷åßùí ôçò óõóôïé÷ßáò íá ãßíåôáé
áõôüìáôá êáôÜ ôç äéáäéêáóßá åêêßíçóçò ôïõ óõóôÞìáôïò:</para>
<programlisting>/dev/raid3/gr0p1 /multimedia ufs rw 2 2</programlisting>
</step>
</procedure>
</sect2>
</sect1>
<sect1 id="geom-ggate">
<title>ÄéêôõáêÝò ÓõóêåõÝò ìÝóù GEOM Gate</title>
<para>Ôï GEOM õðïóôçñßæåé áðïìáêñõóìÝíç ÷ñÞóç óõóêåõþí, üðùò ïé óêëçñïß
äßóêïé, ôá CD-ROM, ôá áñ÷åßá ê.ë.ð. ÷ñçóéìïðïéþíôáò ôá âïçèçôéêÜ
ðñïãñÜììáôá ðýëçò (gate). Ç ëåéôïõñãßá åßíáé ðáñüìïéá ìå ôï
<acronym>NFS</acronym>.</para>
<para>Ãéá íá îåêéíÞóåôå, ðñÝðåé íá äçìéïõñãÞóåôå Ýíá áñ÷åßï exports. Ôï
áñ÷åßï áõôü êáèïñßæåé ðïéïò åðéôñÝðåôáé íá áðïêôÞóåé ðñüóâáóç óôïõò
êïéíü÷ñçóôïõò ðüñïõò êáé ôé åðéðÝäïõ èá åßíáé áõôÞ ç ðñüóâáóç. Ãéá
ðáñÜäåéãìá, ãéá íá äéáìïéñÜóåôå ôçí ôÝôáñôç êáôÜôìçóç (slice) ôïõ ðñþôïõ
äßóêïõ <acronym>SCSI</acronym>, åßíáé áñêåôü íá äçìéïõñãÞóåôå ôï
ðáñáêÜôù áñ÷åßï <filename>/etc/gg.exports</filename>:</para>
<programlisting>192.168.1.0/24 RW /dev/da0s4d</programlisting>
<para>Ôï ðáñáðÜíù èá åðéôñÝøåé óå üëïõò ôïõò õðïëïãéóôÝò ôïõ éäéùôéêïý
óáò äéêôýïõ, íá Ý÷ïõí ðñüóâáóç ìÝóù äéêôýïõ óôï óýóôçìá áñ÷åßùí ôçò
êáôÜôìçóçò <devicename>da0s4d</devicename>.</para>
<para>Ãéá íá äéáìïéñÜóåôå áõôÞ ôç óõóêåõÞ, âåâáéùèåßôå üôé äåí åßíáé
ðñïóáñôçìÝíç ôç äåäïìÝíç óôéãìÞ, êáé îåêéíÞóôå ôï äáßìïíá åîõðçñåôçôÞ
&man.ggated.8;:</para>
<screen>&prompt.root; <userinput>ggated</userinput></screen>
<para>Ãéá íá ðñïóáñôÞóåôå ôçí óõóêåõÞ óôï ìç÷Üíçìá ðåëÜôç, ÷ñçóéìïðïéÞóôå
ôéò áêüëïõèåò åíôïëÝò:</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>Áðü åäþ êáé óôï åîÞò, ìðïñåßôå íá Ý÷åôå ðñüóâáóç óôç óõóêåõÞ ìÝóù
ôïõ óçìåßïõ ðñïóÜñôçóçò <filename class="directory">/mnt</filename>.</para>
<note>
<para>ÐñÝðåé íá ôïíéóôåß üôé ç äéáäéêáóßá èá áðïôý÷åé áí ç óõóêåõÞ
åßíáé ôç äåäïìÝíç óôéãìÞ ðñïóáñôçìÝíç, åßôå óôïí åîõðçñåôçôÞ, åßôå óå
ïðïéïäÞðïôå Üëëï õðïëïãéóôÞ óôï äßêôõï.</para>
</note>
<para>¼ôáí äåí ÷ñåéÜæåóôå ðëÝïí ôç óõóêåõÞ, ìðïñåßôå íá ôçí
áðïðñïóáñôÞóåôå ìå áóöÜëåéá, ÷ñçóéìïðïéþíôáò ôçí åíôïëÞ &man.umount.8;,
üðùò ãßíåôáé êáé ìå ïðïéáäÞðïôå Üëëç óõóêåõÞ äßóêïõ.</para>
</sect1>
<sect1 id="geom-glabel">
<title>Äçìéïõñãþíôáò ÅôéêÝôåò (Labels) óôéò ÓõóêåõÝò Äßóêùí</title>
<indexterm>
<primary>GEOM</primary>
</indexterm>
<indexterm>
<primary>Disk Labels</primary>
</indexterm>
<para>ÊáôÜ ôç äéÜñêåéá ôçò áñ÷éêïðïßçóçò, óôçí åêêßíçóç ôïõ óõóôÞìáôïò,
ï ðõñÞíáò ôïõ &os; èá äçìéïõñãÞóåé ôá áðáñáßôçôá áñ÷åßá ãéá êÜèå
óõóêåõÞ ðïõ áíé÷íåýåé. ÁõôÞ ç ìÝèïäïò áíß÷íåõóçò óõóêåõþí, ìðïñåß íá
äçìéïõñãÞóåé ðñïâëÞìáôá. Ãéá ðáñÜäåéãìá, ôé èá ãßíåé áí ðñïóèÝóïõìå Ýíá
íÝï äßóêï <acronym>USB</acronym>; Åßíáé áñêåôÜ ðéèáíü ìéá óõóêåõÞ
ìíÞìçò flash íá ðÜñåé ôï üíïìá <devicename>da0</devicename> êáé ç
áñ÷éêÞ <devicename>da0</devicename> íá ìåôáêéíçèåß óôï
<devicename>da1</devicename>. Áõôü èá ðñïêáëÝóåé ðñïâëÞìáôá óôçí
ðñïóÜñôçóç ôùí óõóôçìÜôùí áñ÷åßùí, áí õðÜñ÷ïõí ïé áíôßóôïé÷åò
êáôá÷ùñßóåéò ôïõò óôï <filename>/etc/fstab</filename>, êáé ìðïñåß áêüìá
êáé íá ðáñåìðïäßóåé ôçí êáíïíéêÞ åêêßíçóç ôïõ óõóôÞìáôïò.</para>
<para>Ìéá ëýóç åßíáé íá ñõèìßóåôå ôéò óõóêåõÝò <acronym>SCSI</acronym> ìå
ôÝôïéï ôñüðï, þóôå ç áñßèìçóç ôïõò íá åßíáé óõíå÷üìåíç. ¸ôóé, êÜèå
öïñÜ ðïõ ðñïóèÝôåôå ìéá íÝá óõóêåõÞ óôïí åëåãêôÞ <acronym>SCSI</acronym>
èá åßóôå óßãïõñïò üôé èá ëÜâåé áñéèìü ðïõ äåí Ý÷åé ÷ñçóéìïðïéçèåß.
ÁëëÜ ôé ãßíåôáé ìå ôéò óõóêåõÝò <acronym>USB</acronym> ðïõ ìðïñåß íá
áíôéêáôáóôÞóïõí ôïí êýñéï <acronym>SCSI</acronym> äßóêï; Áõôü ìðïñåß
ðñÜãìáôé íá óõìâåß, êáèþò ïé óõóêåõÝò <acronym>USB</acronym>
áíé÷íåýïíôáé êáôÜ âÜóç ðñéí áðü ôïí åëåãêôÞ <acronym>SCSI</acronym>.
Ìéá ëýóç åßíáé íá âÜæåôå ôéò óõóêåõÝò áõôÝò ìüíï ìåôÜ ôçí åêêßíçóç
ôïõ óõóôÞìáôïò. Ìéá Üëëç ìÝèïäïò åßíáé íá ÷ñçóéìïðïéåßôå ìüíï ìéá
óõóêåõÞ ôýðïõ <acronym>ATA</acronym> êáé íá ìçí êáôá÷ùñåßôå ðïôÝ ôïõò
äßóêïõò <acronym>SCSI</acronym> óôï <filename>/etc/fstab</filename>.</para>
<para>ÕðÜñ÷åé ùóôüóï êáëýôåñç ëýóç. ×ñçóéìïðïéþíôáò ôï âïçèçôéêü
ðñüãñáììá <command>glabel</command>, Ýíáò äéá÷åéñéóôÞò Þ ÷ñÞóôçò, ìðïñåß
íá áðïäþóåé åôéêÝôåò óôéò óõóêåõÝò äßóêùí êáé íá ôéò ÷ñçóéìïðïéÞóåé óôï
<filename>/etc/fstab</filename>, áíôß ãéá ôá óõìâáôéêÜ ïíüìáôá
óõóêåõþí. ÅðåéäÞ ç <command>glabel</command> áðïèçêåýåé ôçí åôéêÝôá
óôïí ôåëåõôáßï ôïìÝá ôïõ êÜèå ðáñï÷Ýá (óõóêåõÞò äßóêïõ), ç åôéêÝôá
äéáôçñåßôáé êáé ìåôÜ áðü ôçí åðáíåêêßíçóç ôïõ óõóôÞìáôïò.
×ñçóéìïðïéþíôáò áõôÞ ôçí åôéêÝôá ùò üíïìá óõóêåõÞò, èá ìðïñåßôå íá
ðñïóáñôÞóåôå ðÜíôá ôï óýóôçìá áñ÷åßùí, Üó÷åôá ìå ôï ðñáãìáôéêü üíïìá
óõóêåõÞò ðïõ Ý÷åé áðïäïèåß óôï äßóêï.</para>
<note>
<para>Äåí ÷ñåéÜæåôáé öõóéêÜ íá ôïíßóïõìå üôé áõôÞ ç åôéêÝôá èá ðñÝðåé
íá åßíáé ìüíéìç. Ôï âïçèçôéêü ðñüãñáììá <command>glabel</command>
ìðïñåß íá äçìéïõñãÞóåé ôüóï ìüíéìåò üóï êáé ðñïóùñéíÝò åôéêÝôåò.
Ìüíï ïé ìüíéìåò åôéêÝôåò äéáôçñïýíôáé áíÝðáöåò ìåôÜ áðü ìéá
åðáíåêêßíçóç. Äåßôå ôç óåëßäá manual ôçò &man.glabel.8; ãéá
ðåñéóóüôåñåò ðëçñïöïñßåò ó÷åôéêÜ ìå ôá åßäç ôùí åôéêåôþí.</para>
</note>
<sect2>
<title>Åßäç Åôéêåôþí êáé Ðáñáäåßãìáôá</title>
<para>ÕðÜñ÷ïõí äýï ôýðïé åôéêåôþí, ç ãåíéêÞ åôéêÝôá êáé ç åôéêÝôá
óõóôÞìáôïò áñ÷åßùí. Ïé åôéêÝôåò ìðïñåß íá åßíáé ðñïóùñéíÝò Þ ìüíéìåò.
Ïé ìüíéìåò åôéêÝôåò ìðïñïýí íá äçìéïõñãçèïýí ìå ôéò åíôïëÝò
&man.tunefs.8; Þ &man.newfs.8;. Óôçí ðåñßðôùóç áõôÞ, èá äçìéïõñãçèïýí
óå Ýíá õðïêáôÜëïãï ôïõ <filename class="directory">/dev</filename>.
Ãéá ðáñÜäåéãìá, ïé åôéêÝôåò óõóêåõþí ìå óýóôçìá áñ÷åßùí
<acronym>UFS</acronym>2, èá äçìéïõñãçèïýí óôïí êáôÜëïãï <filename
class="directory">/dev/ufs</filename>. Ìüíéìåò åôéêÝôåò ìðïñïýí
åðßóçò íá äçìéïõñãçèïýí ìå ÷ñÞóç ôçò åíôïëÞò
<command>glabel label</command>. Ïé åôéêÝôåò áõôÝò äåí åîáñôþíôáé áðü
ôï óýóôçìá áñ÷åßùí, êáé äçìéïõñãïýíôáé óôïí êáôÜëïãï
<filename class="directory">/dev/label</filename>.</para>
<para>Ïé åôéêÝôåò ðñïóùñéíïý ôýðïõ, ÷Üíïíôáé óå êÜèå åðáíåêêßíçóç ôïõ
óõóôÞìáôïò. Ïé åôéêÝôåò áõôÝò äçìéïõñãïýíôáé óôïí êáôÜëïãï
<filename class="directory">/dev/label</filename> êáé åßíáé ôÝëåéåò
ãéá ðåéñáìáôéóìïýò. Ìðïñåßôå íá äçìéïõñãÞóåôå ðñïóùñéíÝò åôéêÝôåò
ìå ôçí åíôïëÞ <command>glabel create</command>. Ãéá ðåñéóóüôåñåò
ðëçñïöïñßåò, äéáâÜóôå ôç óåëßäá manual ôçò &man.glabel.8;.</para>
<!-- XXXTR: How do you create a file system label without running newfs
or when there is no newfs (e.g.: cd9660)? -->
<para>Ãéá íá äçìéïõñãÞóåôå ìéá ìüíéìç åôéêÝôá ãéá Ýíá óýóôçìá áñ÷åßùí
<acronym>UFS</acronym>2, ÷ùñßò íá êáôáóôñÝøåôå ôá äåäïìÝíá ðïõ
ðåñéÝ÷åé, ÷ñçóéìïðïéÞóôå ôçí áêüëïõèç åíôïëÞ:</para>
<screen>&prompt.root; <userinput>tunefs -L <replaceable>home</replaceable> <replaceable>/dev/da3</replaceable></userinput></screen>
<warning>
<para>Áí ôï óýóôçìá áñ÷åßùí åßíáé ãåìÜôï, ç ðáñáðÜíù åíôïëÞ ìðïñåß íá
ðñïêáëÝóåé êáôáóôñïöÞ äåäïìÝíùí. Ùóôüóï, áí ôï óýóôçìá áñ÷åßùí
åßíáé ãåìÜôï, óôü÷ïò óáò èá ðñÝðåé íá åßíáé íá äéáãñÜøåôå ôá
áñ÷åßá ðïõ äåí ÷ñçóéìïðïéïýíôáé, êáé ü÷é íá ðñïóèÝôåôå
åôéêÝôåò.</para>
</warning>
<para>Èá ðñÝðåé ôþñá íá õðÜñ÷åé ìéá åôéêÝôá óôïí êáôÜëïãï
<filename class="directory">/dev/ufs</filename> ç ïðïßá ìðïñåß íá
ðñïóôåèåß óôï <filename>/etc/fstab</filename>:</para>
<programlisting>/dev/ufs/home /home ufs rw 2 2</programlisting>
<note>
<para>Ôï óýóôçìá áñ÷åßùí äåí ðñÝðåé íá åßíáé ðñïóáñôçìÝíï êáèþò
åêôåëåßôå ôçí åíôïëÞ <command>tunefs</command>.</para>
</note>
<para>Ìðïñåßôå ôþñá íá ðñïóáñôÞóåôå ôï óýóôçìá áñ÷åßùí ìå ôï óõíÞèç
ôñüðï:</para>
<screen>&prompt.root; <userinput>mount /home</userinput></screen>
<para>Áðü åäþ êáé ðÝñá, êáé üóï ôï Üñèñùìá
<filename>geom_label.ko</filename> öïñôþíåôáé óôïí ðõñÞíá ìÝóù ôïõ
<filename>/boot/loader.conf</filename> Þ åöüóïí Ý÷åôå âÜëåé ôçí
åðéëïãÞ <literal>GEOM_LABEL</literal> óôïí ðõñÞíá óáò, áêüìá êáé áí
ôï üíïìá ôçò óõóêåõÞò áëëÜîåé, äåí èá Ý÷åé êáìéÜ äõóìåíÞ åðßäñáóç
óôï óýóôçìá óáò.</para>
<para>Ìðïñåßôå åðßóçò íá äçìéïõñãÞóåôå óõóôÞìáôá áñ÷åßùí ìå
ðñïåðéëåãìÝíç åôéêÝôá, ÷ñçóéìïðïéþíôáò ôçí åðéëïãÞ
<option>-L</option> óôçí åíôïëÞ <command>newfs</command>. Äåßôå ôçí
óåëßäá manual ôïõ &man.newfs.8; ãéá ðåñéóóüôåñåò ðëçñïöïñßåò.</para>
<para>Ìðïñåßôå íá ÷ñçóéìïðïéÞóåôå ôçí ðáñáêÜôù åíôïëÞ ãéá íá
êáôáóôñÝøåôå ìéá åôéêÝôá:</para>
<screen>&prompt.root; <userinput>glabel destroy home</userinput></screen>
<para>Ôï åðüìåíï ðáñÜäåéãìá äåß÷íåé ðùò ìðïñïýí íá äïèïýí åôéêÝôåò óôéò
êáôáôìÞóåéò ôïõ äßóêïõ åêêßíçóçò.</para>
<example>
<title>Äçìéïõñãßá Åôéêåôþí óôéò ÊáôáôìÞóåéò ôïõ Äßóêïõ
Åêêßíçóçò</title>
<para>Äçìéïõñãþíôáò ìüíéìåò åôéêÝôåò óôéò êáôáôìÞóåéò ôïõ äßóêïõ
åêêßíçóçò, ôï óýóôçìá óáò èá óõíå÷ßóåé íá åêêéíåß êáíïíéêÜ áêüìá
êáé áí ìåôáöÝñåôå ôï äßóêï óå Üëëï åëåãêôÞ Þ áêüìá êáé óå
äéáöïñåôéêü óýóôçìá. Óôï ðáñÜäåéãìá ìáò, èåùñïýìå üôé
÷ñçóéìïðïéåßôáé Ýíáò äßóêïò <acronym>ATA</acronym>, ï ïðïßïò
áíáãíùñßæåôáé áðü ôï óýóôçìá ùò <devicename>ad0</devicename>.
Èåùñïýìå åðßóçò üôé ÷ñçóéìïðïéåßôáé ç óõíçèéóìÝíç äéÜôáîç
êáôáôìÞóåùí ôïõ &os;, ðïõ ðåñéëáìâÜíåé ôéò êáôáôìÞóåéò
<filename class="directory">/</filename>,
<filename class="directory">/var</filename>,
<filename class="directory">/usr</filename> êáé
<filename class="directory">/tmp</filename> üðùò åðßóçò êáé ìéá
êáôÜôìçóç swap.</para>
<para>ÅðáíåêêéíÞóôå ôï óýóôçìá, êáé üôáí åìöáíéóôåß ç ðñïôñïðÞ ôïõ
&man.loader.8;, ðéÝóôå ôï <keycap>4</keycap> ãéá íá ðñáãìáôïðïéçèåß
åêêßíçóç óå êáôÜóôáóç åíüò ÷ñÞóôç. ¸ðåéôá, äþóôå ôéò áêüëïõèåò
åíôïëÝò:</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>Ç åêêßíçóç èá óõíå÷éóôåß êáíïíéêÜ êáé ôï óýóôçìá èá Ýëèåé óå
êáôÜóôáóç ðïëëáðëþí ÷ñçóôþí (multi-user).
ÌåôÜ ôï ôÝëïò ôçò åêêßíçóçò, åðåîåñãáóôåßôå ôï áñ÷åßï
<filename>/etc/fstab</filename> êáé áëëÜîôå ôá óõìâáôéêÜ ïíüìáôá
óõóêåõþí ìå ôéò áíôßóôïé÷åò åôéêÝôåò. Ôï ôåëéêü áñ÷åßï
<filename>/etc/fstab</filename> èá ìïéÜæåé ìå ôï ðáñáêÜôù:</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>Ìðïñåßôå ôþñá íá åðáíåêêéíÞóåôå ôï óýóôçìá. Áí üëá ðÞãáí êáëÜ,
ç åêêßíçóç èá åßíáé êáíïíéêÞ, êáé ç åíôïëÞ <command>mount</command>
èá äåßîåé:</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>Îåêéíþíôáò áðü ôï &os; 7.2, ôï &man.glabel.8; õðïóôçñßæåé
Ýíá íÝï åßäïò åôéêÝôáò ãéá óõóôÞìáôá áñ÷åßùí <acronym>UFS</acronym>,
ðïõ âáóßæåôáé óå Ýíá ìïíáäéáßï áíáãíùñéóôéêü ôïõò,
ôï <literal>ufsid</literal>. Ïé åôéêÝôåò áõôÝò âñßóêïíôáé óôïí
êáôÜëïãï <filename class="directory">/dev/ufsid</filename>,
äçìéïõñãïýíôáé áõôüìáôá êáôÜ ôçí åêêßíçóç ôïõ óõóôÞìáôïò êáé åßíáé
äõíáôüí íá ÷ñçóéìïðïéçèïýí ãéá ôçí ðñïóÜñôçóç êáôáôìÞóåùí ìÝóù ôïõ
<filename>/etc/fstab</filename>. Ìðïñåßôå íá ÷ñçóéìïðïéÞóåôå ôçí
åíôïëÞ <command>glabel status</command> ãéá íá ëÜâåôå ìéá ëßóôá
ôùí óõóôçìÜôùí áñ÷åßùí ìå ôéò áíôßóôïé÷åò <literal>ufsid</literal>
åôéêÝôåò ôïõò:</para>
<screen>&prompt.user; <userinput>glabel status</userinput>
Name Status Components
ufsid/486b6fc38d330916 N/A ad4s1d
ufsid/486b6fc16926168e N/A ad4s1f</screen>
<para>Óôï ðáñáðÜíù ðáñÜäåéãìá, ôï <devicename>ad4s1d</devicename>
áíôéðñïóùðåýåé ôï óýóôçìá áñ÷åßùí <filename
class="directory">/var</filename>, åíþ ôï
<devicename>ad4s1f</devicename> áíôéðñïóùðåýåé ôï óýóôçìá áñ÷åßùí
<filename class="directory">/usr</filename>. ×ñçóéìïðïéþíôáò ôéò
ôéìÝò <literal>ufsid</literal> ðïõ öáßíïíôáé, ç ðñïóÜñôçóç áõôþí
ôùí êáôáôìÞóåùí ìðïñåß íá ãßíåé ìå ôéò ðáñáêÜôù êáôá÷ùñßóåéò óôï
<filename>/etc/fstab</filename>:</para>
<programlisting>/dev/ufsid/486b6fc38d330916 /var ufs rw 2 2
/dev/ufsid/486b6fc16926168e /usr ufs rw 2 2</programlisting>
<para>ÏðïéáäÞðïôå êáôÜôìçóç äéáèÝôåé áíáãíùñéóôéêü
<literal>ufsid</literal> ìðïñåß íá ðñïóáñôçèåß ìå ôïí ßäéï ôñüðï,
÷ùñßò íá õðÜñ÷åé ðëÝïí áíÜãêç íá äçìéïõñãçèåß ìüíéìç åôéêÝôá
÷åéñïêßíçôá. Ç ðñïóÜñôçóç ìÝóù åôéêÝôáò <literal>ufsid</literal>,
ðáñÝ÷åé ôï ðëåïíÝêôçìá ôçò áíåîáñôçóßáò áðü ôï üíïìá óõóêåõÞò, ôï
ïðïßï ðáñÝ÷ïõí êáé ïé ìüíéìåò åôéêÝôåò.</para>
</sect2>
</sect1>
<sect1 id="geom-gjournal">
<title>UFS Journaling ÌÝóù GEOM</title>
<indexterm>
<primary>GEOM</primary>
</indexterm>
<indexterm>
<primary>Journaling</primary>
</indexterm>
<para>Óôçí Ýêäïóç 7.0 ôïõ &os; õëïðïéåßôáé ãéá ðñþôç öïñÜ ç íÝá (êáé áðü
ðïëëïýò áíáìåíüìåíç) äõíáôüôçôá ãéá ÷ñÞóç çìåñïëïãßïõ (journal) óôï
óýóôçìá áñ÷åßùí. Ç õëïðïßçóç ðáñÝ÷åôáé ìÝóù ôïõ
õðïóõóôÞìáôïò <acronym>GEOM</acronym> êáé ìðïñåß íá ñõèìéóôåß åýêïëá
ìÝóù ôïõ âïçèçôéêïý ðñïãñÜììáôïò &man.gjournal.8;.</para>
<para>Ôé åßíáé ôï journaling; Ôï journaling áðïèçêåýåé óå Ýíá áñ÷åßï
êáôáãñáöÞò (log, çìåñïëüãéï, Þ áðëþò journal) ôéò óõíáëëáãÝò ôïõ
óõóôÞìáôïò áñ÷åßùí. ÐáñÜäåéãìá óõíáëëáãÞò åßíáé ïé áëëáãÝò ðïõ
áðáéôïýíôáé ãéá ìéá ðëÞñç äéáäéêáóßá åããñáöÞò óôï äßóêï. ¸ôóé, óôï
log áðïèçêåýïíôáé ïé áëëáãÝò óôá ìåôá-äåäïìÝíá (meta-data) êáé óôá ßäéá
ôá áñ÷åßá, ðñéí ãßíåé ç ôåëéêÞ (êáíïíéêÞ) áðïèÞêåõóç ôïõò óôï äßóêï.
Ôï áñ÷åßï êáôáãñáöÞò ìðïñåß áñãüôåñá íá îáíá÷ñçóéìïðïéçèåß þóôå ç
óõíáëëáãÞ íá ãßíåé áðü ôçí áñ÷Þ, åîáóöáëßæïíôáò ìå áõôü ôïí ôñüðï üôé
ôï óýóôçìá áñ÷åßùí èá ðáñáìåßíåé óå óôáèåñÞ êáôÜóôáóç.</para>
<para>Ðñüêåéôáé ïõóéáóôéêÜ ãéá ìéá áêüìá ìÝèïäï ðñïöýëáîçò áðü áðþëåéá
äåäïìÝíùí êáé áóõíÝðåéåò óôï óýóôçìá áñ÷åßùí. Óå áíôßèåóç ìå ôá
Soft Updates ôá ïðïßá åíôïðßæïõí êáé õðï÷ñåþíïõí ôçí Üìåóç åããñáöÞ
ôùí ìåôá-äåäïìÝíùí, êáé ôùí óôéãìéïôýðùí (Snapshots) ôá ïðïßá åßíáé
åéêüíåò ôïõ óõóôÞìáôïò áñ÷åßùí óå ìéá äåäïìÝíç óôéãìÞ, ôï log
áðïèçêåýåôáé óå ÷þñï ðïõ Ý÷åé åê÷ùñçèåß åéäéêÜ ãéá áõôü ôï
óêïðü, êáé óå ìåñéêÝò ðåñéðôþóåéò ìðïñåß íá áðïèçêåýåôáé óå åíôåëþò
äéáöïñåôéêü äßóêï.</para>
<para>Óå áíôßèåóç ìå õëïðïéÞóåéò journaling óå Üëëá óõóôÞìáôá áñ÷åßùí,
ç ìÝèïäïò <command>gjournal</command> âáóßæåôáé óå blocks, êáé äåí
õëïðïéåßôáé ùò ìÝñïò ôïõ óõóôÞìáôïò áñ÷åßùí, áëëÜ ìüíï ùò åðÝêôáóç ôïõ
<acronym>GEOM</acronym>.</para>
<para>Ãéá åíåñãïðïßçóç ôçò õðïóôÞñéîçò <command>gjournal</command>, èá
ðñÝðåé íá õðÜñ÷åé ç ðáñáêÜôù åðéëïãÞ óôïí ðõñÞíá ôïõ &os;. Ç åðéëïãÞ
áõôÞ õðÜñ÷åé áðü ðñïåðéëïãÞ óôçí Ýêäïóç 7.0 êáé üëåò ôéò íåüôåñåò
åêäüóåéò ôïõ &os;.</para>
<programlisting>options UFS_GJOURNAL</programlisting>
<para>Áí ÷ñåéÜæåôáé íá ðñïóáñôþíôáé ôüìïé ìå journaling êáôÜ ôçí åêêßíçóç,
èá ðñÝðåé åðßóçò íá öïñôþíåôáé áõôüìáôá êáé ôï Üñèñùìá ðõñÞíá
<filename>geom_journal.ko</filename>. Ãéá ôï óêïðü áõôü, ðñïóèÝóôå ôçí
ðáñáêÜôù ãñáììÞ óôï áñ÷åßï <filename>/boot/loader.conf</filename>:</para>
<programlisting>geom_journal_load="YES"</programlisting>
<para>ÅíáëëáêôéêÜ, ç ëåéôïõñãßá áõôÞ ìðïñåß íá åíóùìáôùèåß óå Ýíá
ðñïóáñìïóìÝíï ðõñÞíá, ìå ôçí ðñïóèÞêç ôçò ðáñáêÜôù ãñáììÞò óôï
áíôßóôïé÷ï áñ÷åßï ñõèìßóåùí:</para>
<programlisting>options GEOM_JOURNAL</programlisting>
<para>Ç äçìéïõñãßá journal óå Ýíá åëåýèåñï óýóôçìá áñ÷åßùí, ìðïñåß ôþñá
íá ãßíåé ìå ôá áêüëïõèá âÞìáôá, èåùñþíôáò üôé ç óõóêåõÞ
<devicename>da4</devicename> åßíáé Ýíáò íÝïò äßóêïò
<acronym>SCSI</acronym>:</para>
<screen>&prompt.root; <userinput>gjournal load</userinput>
&prompt.root; <userinput>gjournal label /dev/da4</userinput></screen>
<para>Óôï óçìåßï áõôü èá õðÜñ÷åé ìéá óõóêåõÞ
<devicename>/dev/da4</devicename> êáèþò êáé ìéá óõóêåõÞ
<devicename>/dev/da4.journal</devicename>. Óôç óõóêåõÞ áõôÞ ìðïñåßôå
ôþñá íá äçìéïõñãÞóåôå óýóôçìá áñ÷åßùí:</para>
<screen>&prompt.root; <userinput>newfs -O 2 -J /dev/da4.journal</userinput></screen>
<para>Ç ðáñáðÜíù åíôïëÞ èá äçìéïõñãÞóåé Ýíá óýóôçìá áñ÷åßùí
<acronym>UFS</acronym>2 óôç
óõóêåõÞ <devicename>/dev/da4.journal</devicename>, ç ïðïßá Ý÷åé
Þäç õðïóôÞñéîç ãéá journaling.</para>
<para>Ìðïñåßôå íá ÷ñçóéìïðïéÞóåôå ôçí åíôïëÞ <command>mount</command>
ãéá íá ðñïóáñôÞóåôå ôçí óõóêåõÞ óôï åðéèõìçôü óçìåßï ðñïóÜñôçóçò, üðùò
öáßíåôáé ðáñáêÜôù:</para>
<screen>&prompt.root; <userinput>mount /dev/da4.journal <replaceable>/mnt</replaceable></userinput></screen>
<note>
<para>Óôçí ðåñßðôùóç áñêåôþí slice, èá äçìéïõñãçèåß Ýíá journal ãéá êÜèå
åðéìÝñïõò slice. Ãéá ðáñÜäåéãìá, áí õðÜñ÷ïõí ôá slices
<devicename>ad4s1</devicename> êáé <devicename>ad4s2</devicename>
ôüôå ôï <command>gjournal</command> èá äçìéïõñãÞóåé ôéò óõóêåõÝò
<devicename>ad4s1.journal</devicename> êáé
<devicename>ad4s2.journal</devicename>.</para>
</note>
<para>Ãéá êáëýôåñç áðüäïóç, ßóùò åßíáé åðéèõìçôÞ ç ôÞñçóç ôïõ
journal óå äéáöïñåôéêü äßóêï. Ãéá ôéò ðåñéðôþóåéò áõôÝò, ï ðáñï÷Ýáò
çìåñïëïãßïõ (ç óõóêåõÞ äßóêïõ ðïõ èá ðåñéÝ÷åé ôï journal) ðñÝðåé
íá äßíåôáé ùò ðáñÜìåôñïò óôçí åíôïëÞ, áìÝóùò ìåôÜ ôç óõóêåõÞ äßóêïõ
óôçí ïðïßá èá åíåñãïðïéçèåß ôï journaling. Ìðïñåßôå åðßóçò íá
åíåñãïðïéÞóåôå ôï journaling óå õðÜñ÷ïíôá óõóôÞìáôá áñ÷åßùí
÷ñçóéìïðïéþíôáò ôçí åíôïëÞ <command>tunefs</command>. Ùóôüóï, èá ðñÝðåé
íá êñáôÞóåôå áíôßãñáöï áóöáëåßáò ôùí áñ÷åßùí óáò, ðñéí åðé÷åéñÞóåôå
íá êÜíåôå áëëáãÝò óå Ýíá õðÜñ÷ïí óýóôçìá áñ÷åßùí. Óôéò ðåñéóóüôåñåò
ðåñéðôþóåéò, ç <command>tunefs</command> èá áðïôý÷åé áí äåí ìðïñÝóåé
íá äçìéïõñãÞóåé ôï journal, áëëÜ áõôü äåí óáò ðñïóôáôåýåé áðü áðþëåéá
äåäïìÝíùí ðïõ ìðïñåß íá ðñïÝëèåé áðü êáêÞ ÷ñÞóç ôçò
<command>tunefs</command>.</para>
<para>Åßíáé åðßóçò äõíáôüí íá ÷ñçóéìïðïéçèåß journaling óôïí äßóêï
åêêßíçóçò åíüò óõóôÞìáôïò &os;. ÄéáâÜóôå ôï Üñèñï <ulink
url="&url.articles.gjournal-desktop;">Õëïðïßçóç ôïõ UFS Journaling óå
Ýíá Desktop ÕðïëïãéóôÞ</ulink> ãéá ëåðôïìåñåßò ïäçãßåò.</para>
</sect1>
</chapter>