Date: Mon, 24 Jun 2013 01:00:56 +0000 (UTC) From: Warren Block <wblock@FreeBSD.org> To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r42018 - head/en_US.ISO8859-1/books/handbook/disks Message-ID: <201306240100.r5O10ul6056816@svn.freebsd.org>
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Author: wblock Date: Mon Jun 24 01:00:56 2013 New Revision: 42018 URL: http://svnweb.freebsd.org/changeset/doc/42018 Log: Suppress some ugly memories in the Storage chapter: * Remove "RAID" section that only covers ccd(4) and ataraid(4). These may still work, but there are better solutions for new users. * Remove Backups to Floppies section. * Add SATA drive names. * Change CDROM to CD-ROM to match the FDP Primer word list. About ccd(4): Once new and useful, thrice ousted from its niche, time's arrow evicts ccd from the Handbook, to live forever in the archives. Modified: head/en_US.ISO8859-1/books/handbook/disks/chapter.xml Modified: head/en_US.ISO8859-1/books/handbook/disks/chapter.xml ============================================================================== --- head/en_US.ISO8859-1/books/handbook/disks/chapter.xml Mon Jun 24 00:46:26 2013 (r42017) +++ head/en_US.ISO8859-1/books/handbook/disks/chapter.xml Mon Jun 24 01:00:56 2013 (r42018) @@ -52,19 +52,11 @@ </listitem> <listitem> - <para>The various storage media options for backups.</para> - </listitem> - - <listitem> <para>How to use the backup programs available under &os;.</para> </listitem> <listitem> - <para>How to backup to floppy disks.</para> - </listitem> - - <listitem> <para>What file system snapshots are and how to use them efficiently.</para> </listitem> @@ -84,7 +76,7 @@ <title>Device Names</title> <para>The following is a list of physical storage devices - supported in &os;, and their associated device names.</para> + supported in &os; and their associated device names.</para> <table id="disk-naming-physical-table" frame="none"> <title>Physical Disk Naming Conventions</title> @@ -100,27 +92,40 @@ <tbody> <row> <entry>IDE hard drives</entry> - <entry><literal>ad</literal></entry> + <entry><literal>ad</literal> or + <literal>ada</literal></entry> </row> <row> - <entry>IDE CDROM drives</entry> - <entry><literal>acd</literal></entry> + <entry>IDE CD-ROM drives</entry> + <entry><literal>acd</literal> or + <literal>cd</literal></entry> </row> <row> + <entry>SATA hard drives</entry> + <entry><literal>ad</literal> or + <literal>ada</literal></entry> + </row> + + <row> + <entry>SATA CD-ROM drives</entry> + <entry><literal>acd</literal> or + <literal>cd</literal></entry> + </row> + <row> <entry>SCSI hard drives and USB Mass storage devices</entry> <entry><literal>da</literal></entry> </row> <row> - <entry>SCSI CDROM drives</entry> + <entry>SCSI CD-ROM drives</entry> <entry><literal>cd</literal></entry> </row> <row> - <entry>Assorted non-standard CDROM drives</entry> + <entry>Assorted non-standard CD-ROM drives</entry> <entry><literal>mcd</literal> for Mitsumi CD-ROM and <literal>scd</literal> for Sony CD-ROM devices</entry> </row> @@ -242,362 +247,6 @@ <screen>&prompt.root; <userinput>mount /newdisk</userinput></screen> </sect1> - <sect1 id="raid"> - <title>RAID</title> - - <sect2 id="raid-soft"> - <title>Software RAID</title> - - <sect3 id="ccd"> - <sect3info> - <authorgroup> - <author> - <firstname>Christopher</firstname> - <surname>Shumway</surname> - <contrib>Original work by </contrib> - </author> - </authorgroup> - - <authorgroup> - <author> - <firstname>Jim</firstname> - <surname>Brown</surname> - <contrib>Revised by </contrib> - </author> - </authorgroup> - </sect3info> - - <title>Concatenated Disk Driver (CCD) Configuration</title> - - <indexterm><primary>RAID</primary><secondary>software</secondary></indexterm> - <indexterm><primary>RAID</primary><secondary>CCD</secondary></indexterm> - - <para>When choosing a mass storage solution, the most - important factors to consider are speed, reliability, and - cost. It is rare to have all three in balance. Normally a - fast, reliable mass storage device is expensive, and to cut - back on cost either speed or reliability must be - sacrificed.</para> - - <para>In designing the system described below, cost was - chosen as the most important factor, followed by speed, - then reliability. Data transfer speed for this system is - ultimately constrained by the network. While reliability is - very important, the CCD drive described below serves online - data that is already fully backed up and which can easily be - replaced.</para> - - <para>Defining the requirements is the first step in choosing - a mass storage solution. If the requirements prefer speed - or reliability over cost, the solution will differ from the - system described in this section.</para> - - <sect4 id="ccd-installhw"> - <title>Installing the Hardware</title> - - <para>In addition to the IDE system disk, three Western - Digital 30GB, 5400 RPM IDE disks form the core of the CCD - disk described below, providing approximately 90GB of - online storage. Ideally, each IDE disk would have its own - IDE controller and cable, but to minimize cost, additional - IDE controllers were not used. Instead, the disks were - configured with jumpers so that each IDE controller has - one master, and one slave.</para> - - <para>Upon reboot, the system BIOS was configured to - automatically detect the disks attached. More - importantly, &os; detected them on reboot:</para> - - <programlisting>ad0: 19574MB <WDC WD205BA> [39770/16/63] at ata0-master UDMA33 -ad1: 29333MB <WDC WD307AA> [59598/16/63] at ata0-slave UDMA33 -ad2: 29333MB <WDC WD307AA> [59598/16/63] at ata1-master UDMA33 -ad3: 29333MB <WDC WD307AA> [59598/16/63] at ata1-slave UDMA33</programlisting> - - <note><para>If &os; does not detect all the disks, consult - the drive documentation for proper setup and verify - that the controller is supported by &os;.</para></note> - </sect4> - - <sect4 id="ccd-setup"> - <title>Setting Up the CCD</title> - - <para>The &man.ccd.4; driver takes several identical disks - and concatenates them into one logical file system. In - order to use &man.ccd.4;, its kernel module must be - loaded using &man.ccd.4;. When using a custom kernel, - ensure that this line is compiled in:</para> - - <programlisting>device ccd</programlisting> - - <para>Before configuring &man.ccd.4;, use &man.bsdlabel.8; - to label the disks:</para> - - <programlisting>bsdlabel -w ad1 auto -bsdlabel -w ad2 auto -bsdlabel -w ad3 auto</programlisting> - - <para>This example creates a bsdlabel for - <devicename>ad1c</devicename>, - <devicename>ad2c</devicename> and - <devicename>ad3c</devicename> that spans the entire - disk.</para> - - <para>The next step is to change the disk label type. Use - &man.bsdlabel.8; to edit the disks:</para> - - <programlisting>bsdlabel -e ad1 -bsdlabel -e ad2 -bsdlabel -e ad3</programlisting> - - <para>This opens up the current disk label on each disk with - the editor specified by the <envar>EDITOR</envar> - environment variable, typically &man.vi.1;.</para> - - <para>An unmodified disk label will look something like - this:</para> - - <programlisting>8 partitions: -# size offset fstype [fsize bsize bps/cpg] - c: 60074784 0 unused 0 0 0 # (Cyl. 0 - 59597)</programlisting> - - <para>Add a new <literal>e</literal> partition for - &man.ccd.4; to use. This can usually be copied from the - <literal>c</literal> partition, but the - <option>fstype</option> <emphasis>must</emphasis> be - <userinput>4.2BSD</userinput>. The disk label should now - look something like this:</para> - - <programlisting>8 partitions: -# size offset fstype [fsize bsize bps/cpg] - c: 60074784 0 unused 0 0 0 # (Cyl. 0 - 59597) - e: 60074784 0 4.2BSD 0 0 0 # (Cyl. 0 - 59597)</programlisting> - </sect4> - - <sect4 id="ccd-buildingfs"> - <title>Building the File System</title> - - <para>Now that all the disks are labeled, build the - &man.ccd.4; using &man.ccdconfig.8;, with options similar - to the following:</para> - - <programlisting>ccdconfig ccd0<co id="co-ccd-dev"/> 32<co id="co-ccd-interleave"/> 0<co id="co-ccd-flags"/> /dev/ad1e<co id="co-ccd-devs"/> /dev/ad2e /dev/ad3e</programlisting> - - <para>The use and meaning of each option is described - below:</para> - - <calloutlist> - <callout arearefs="co-ccd-dev"> - <para>The first argument is the device to configure, in - this case, <filename>/dev/ccd0c</filename>. The - <literal>/dev/</literal> portion is optional.</para> - </callout> - - <callout arearefs="co-ccd-interleave"> - <para>The interleave for the file system, which defines - the size of a stripe in disk blocks, each normally 512 - bytes. So, an interleave of 32 would be 16,384 - bytes.</para> - </callout> - - <callout arearefs="co-ccd-flags"> - <para>Flags for &man.ccdconfig.8;. For example, to - enable drive mirroring, specify a flag. This - configuration does not provide mirroring for - &man.ccd.4;, so it is set at 0 (zero).</para> - </callout> - - <callout arearefs="co-ccd-devs"> - <para>The final arguments to &man.ccdconfig.8; are the - devices to place into the array. Use the complete - path name for each device.</para> - </callout> - </calloutlist> - - <para>After running &man.ccdconfig.8; the &man.ccd.4; is - configured and a file system can be installed. Refer to - &man.newfs.8; for options, or run: </para> - - <programlisting>newfs /dev/ccd0c</programlisting> - </sect4> - - <sect4 id="ccd-auto"> - <title>Making it All Automatic</title> - - <para>Generally, &man.ccd.4; should be configured to - automount upon each reboot. To do this, write out the - current configuration to - <filename>/etc/ccd.conf</filename> using the following - command:</para> - - <programlisting>ccdconfig -g > /etc/ccd.conf</programlisting> - - <para>During reboot, the script <command>/etc/rc</command> - runs <command>ccdconfig -C</command> if - <filename>/etc/ccd.conf</filename> exists. This - automatically configures the &man.ccd.4; so it can be - mounted.</para> - - <note> - <para>When booting into single user mode, the following - command must be issued to configure the array before - the &man.ccd.4; can be mounted:</para> - - <programlisting>ccdconfig -C</programlisting> - </note> - - <para>To automatically mount the &man.ccd.4;, place an entry - for the &man.ccd.4; in <filename>/etc/fstab</filename> so - it will be mounted at boot time:</para> - - <programlisting>/dev/ccd0c /media ufs rw 2 2</programlisting> - </sect4> - </sect3> - - <sect3 id="vinum"> - <title>The Vinum Volume Manager</title> - - <indexterm> - <primary>RAID</primary> - <secondary>software</secondary> - </indexterm> - <indexterm> - <primary>RAID</primary> - <secondary>Vinum</secondary> - </indexterm> - - <para>The Vinum Volume Manager is a block device driver which - implements virtual disk drives. It isolates disk hardware - from the block device interface and maps data in ways which - result in an increase in flexibility, performance and - reliability compared to the traditional slice view of disk - storage. &man.vinum.4; implements the RAID-0, RAID-1 and - RAID-5 models, both individually and in combination.</para> - - <para>Refer to <xref linkend="vinum-vinum"/> for more - information about &man.vinum.4;.</para> - </sect3> - </sect2> - - <sect2 id="raid-hard"> - <title>Hardware RAID</title> - - <indexterm> - <primary>RAID</primary> - <secondary>hardware</secondary> - </indexterm> - - <para>&os; also supports a variety of hardware - <acronym>RAID</acronym> controllers. These devices control a - <acronym>RAID</acronym> subsystem without the need for &os; - specific software to manage the array.</para> - - <para>Using an on-card <acronym>BIOS</acronym>, the card - controls most of the disk operations. The following is a - brief setup description using a Promise - <acronym>IDE</acronym> <acronym>RAID</acronym> controller. - When this card is installed and the system is started up, it - displays a prompt requesting information. Follow the - instructions to enter the card's setup screen and to combine - all the attached drives. After doing so, the disks will - look like a single drive to &os;. Other - <acronym>RAID</acronym> levels can be set up - accordingly.</para> - </sect2> - - <sect2> - <title>Rebuilding ATA RAID1 Arrays</title> - - <para>&os; supports the ability to hot-replace a failed disk in - an array.</para> - - <para>An error indicating a failed disk will appear in - <filename>/var/log/messages</filename> or in the &man.dmesg.8; - output:</para> - - <programlisting>ad6 on monster1 suffered a hard error. -ad6: READ command timeout tag=0 serv=0 - resetting -ad6: trying fallback to PIO mode -ata3: resetting devices .. done -ad6: hard error reading fsbn 1116119 of 0-7 (ad6 bn 1116119; cn 1107 tn 4 sn 11)\\ -status=59 error=40 -ar0: WARNING - mirror lost</programlisting> - - <para>Use &man.atacontrol.8; to check for further - information:</para> - - <screen>&prompt.root; <userinput>atacontrol list</userinput> -ATA channel 0: - Master: no device present - Slave: acd0 <HL-DT-ST CD-ROM GCR-8520B/1.00> ATA/ATAPI rev 0 - -ATA channel 1: - Master: no device present - Slave: no device present - -ATA channel 2: - Master: ad4 <MAXTOR 6L080J4/A93.0500> ATA/ATAPI rev 5 - Slave: no device present - -ATA channel 3: - Master: ad6 <MAXTOR 6L080J4/A93.0500> ATA/ATAPI rev 5 - Slave: no device present - -&prompt.root; <userinput>atacontrol status ar0</userinput> -ar0: ATA RAID1 subdisks: ad4 ad6 status: DEGRADED</screen> - - <procedure> - <step> - <para>First, detach the ata channel with the failed disk - so that it can be safely removed:</para> - - <screen>&prompt.root; <userinput>atacontrol detach ata3</userinput></screen> - </step> - - <step> - <para>Replace the disk.</para> - </step> - - <step> - <para>Reattach the ata channel:</para> - - <screen>&prompt.root; <userinput>atacontrol attach ata3</userinput> -Master: ad6 <MAXTOR 6L080J4/A93.0500> ATA/ATAPI rev 5 -Slave: no device present</screen> - </step> - - <step> - <para>Add the new disk to the array as a spare:</para> - - <screen>&prompt.root; <userinput>atacontrol addspare ar0 ad6</userinput></screen> - </step> - - <step> - <para>Rebuild the array:</para> - - <screen>&prompt.root; <userinput>atacontrol rebuild ar0</userinput></screen> - </step> - - <step> - <para>It is possible to check on the progress by issuing the - following command:</para> - - <screen>&prompt.root; <userinput>dmesg | tail -10</userinput> -[output removed] -ad6: removed from configuration -ad6: deleted from ar0 disk1 -ad6: inserted into ar0 disk1 as spare - -&prompt.root; <userinput>atacontrol status ar0</userinput> -ar0: ATA RAID1 subdisks: ad4 ad6 status: REBUILDING 0% completed</screen> - </step> - - <step> - <para>Wait until this operation completes.</para> - </step> - </procedure> - </sect2> - </sect1> - <sect1 id="usb-disks"> <sect1info> <authorgroup> @@ -794,7 +443,7 @@ umass0: detached</screen> <title>Creating and Using CD Media</title> <indexterm> - <primary>CDROMs</primary> + <primary>CD-ROMs</primary> <secondary>creating</secondary> </indexterm> @@ -912,7 +561,7 @@ umass0: detached</screen> of ways.</para> <indexterm> - <primary>CDROMs</primary> + <primary>CD-ROMs</primary> <secondary>creating bootable</secondary> </indexterm> <para>The last option of general use is <option>-b</option>. @@ -955,7 +604,7 @@ umass0: detached</screen> <title><application>burncd</application></title> <indexterm> - <primary>CDROMs</primary> + <primary>CD-ROMs</primary> <secondary>burning</secondary> </indexterm> <para>For an ATAPI CD burner, <command>burncd</command> can be @@ -1001,7 +650,7 @@ umass0: detached</screen> results like this:</para> <indexterm> - <primary>CDROMs</primary> + <primary>CD-ROMs</primary> <secondary>burning</secondary> </indexterm> <screen>&prompt.root; <userinput>cdrecord -scanbus</userinput> @@ -1122,8 +771,8 @@ scsibus1: <para>It is possible to copy a data CD to an image file that is functionally equivalent to the image file created with &man.mkisofs.8;, and then use it to duplicate any data CD. - The example given here assumes that the CDROM device is - <devicename>acd0</devicename>. Substitute the correct CDROM + The example given here assumes that the CD-ROM device is + <devicename>acd0</devicename>. Substitute the correct CD-ROM device.</para> <screen>&prompt.root; <userinput>dd if=/dev/acd0 of=file.iso bs=2048</userinput></screen> @@ -1149,7 +798,7 @@ scsibus1: &man.mount.8; that the file system is of type <literal>ISO9660</literal> by specifying <option>-t cd9660</option> to &man.mount.8;. For example, - to mount the CDROM device, <filename>/dev/cd0</filename>, + to mount the CD-ROM device, <filename>/dev/cd0</filename>, under <filename class="directory">/mnt</filename>, use:</para> @@ -1162,7 +811,7 @@ scsibus1: <screen>&prompt.root; <userinput>mount_cd9660 /dev/cd0 /mnt</userinput></screen> - <para>While data CDROMs from any vendor can be mounted this way, + <para>While data CD-ROMs from any vendor can be mounted this way, disks with certain ISO 9660 extensions might behave oddly. For example, Joliet disks store all filenames in two-byte Unicode characters. The &os; kernel does not speak Unicode, @@ -1186,13 +835,13 @@ scsibus1: </note> <para>Occasionally, <errorname>Device not configured</errorname> - will be displayed when trying to mount a CDROM. This - usually means that the CDROM drive thinks that there is no + will be displayed when trying to mount a CD-ROM. This + usually means that the CD-ROM drive thinks that there is no disk in the tray, or that the drive is not visible on the bus. - It can take a couple of seconds for a CDROM drive to realize + It can take a couple of seconds for a CD-ROM drive to realize that a media is present, so be patient.</para> - <para>Sometimes, a SCSI CDROM may be missed because it did not + <para>Sometimes, a SCSI CD-ROM may be missed because it did not have enough time to answer the bus reset. To resolve this,add the following option to the kernel configuration and <link linkend="kernelconfig-building">rebuild the @@ -1201,7 +850,7 @@ scsibus1: <programlisting>options SCSI_DELAY=15000</programlisting> <para>This tells the SCSI bus to pause 15 seconds during boot, - to give the CDROM drive every possible chance to answer the + to give the CD-ROM drive every possible chance to answer the bus reset.</para> </sect2> @@ -1220,7 +869,7 @@ scsibus1: <screen>&prompt.root; <userinput>tar xzvf /dev/acd1</userinput></screen> - <para>This type of disk can not be mounted as a normal CDROM and + <para>This type of disk can not be mounted as a normal CD-ROM and the data cannot be read under any operating system except &os;. In order to mount the CD, or to share the data with another operating system, &man.mkisofs.8; must be used as @@ -1968,105 +1617,6 @@ cd0: Attempt to query device size failed </sect2> </sect1> - <sect1 id="backups-floppybackups"> - <title>Backups to Floppies</title> - - <sect2 id="floppies-using"> - <title>Can I Use Floppies for Backing Up My Data?</title> - - <indexterm><primary>backup floppies</primary></indexterm> - <indexterm><primary>floppy disks</primary></indexterm> - - <para>Floppy disks are not a suitable media for making backups - as:</para> - - <itemizedlist> - <listitem> - <para>The media is unreliable, especially over long periods - of time.</para> - </listitem> - - <listitem> - <para>Backing up and restoring is very slow.</para> - </listitem> - - <listitem> - <para>They have a very limited capacity.</para> - </listitem> - </itemizedlist> - - <para>However, if no other method of backing up data is - available, floppy disks are better than no backup at - all.</para> - - <para>When backing up to floppy disks, ensure the floppies are - of good quality. Floppies that have been lying around the - office for a couple of years are a bad choice. Ideally, - use new ones from a reputable manufacturer.</para> - </sect2> - - <sect2 id="floppies-creating"> - <title>So How Do I Backup My Data to Floppies?</title> - - <para>The best way to backup to floppy disk is to use - &man.tar.1; with <option>-M</option> (multi-volume), which - allows backups to span multiple floppies.</para> - - <para>To backup all the files in the current directory and - sub-directory, use this as <username>root</username>:</para> - - <screen>&prompt.root; <userinput>tar Mcvf /dev/fd0 *</userinput></screen> - - <para>When the first floppy is full, &man.tar.1; will prompt - to insert the next volume, which in this case is the next - floppy disk:</para> - - <screen>Prepare volume #2 for /dev/fd0 and hit return:</screen> - - <para>This is repeated, with the volume number incrementing, - until all the specified files have been archived.</para> - </sect2> - - <sect2 id="floppies-compress"> - <title>Can I Compress My Backups?</title> - - <indexterm> - <primary><command>tar</command></primary> - </indexterm> - <indexterm> - <primary><command>gzip</command></primary> - </indexterm> - <indexterm><primary>compression</primary></indexterm> - - <para>Unfortunately, &man.tar.1; does not support - <option>-z</option> for multi-volume archives. Instead, - &man.gzip.1; all the files, &man.tar.1; them to the floppies, - then &man.gunzip.1; the files.</para> - </sect2> - - <sect2 id="floppies-restoring"> - <title>How Do I Restore My Backups?</title> - - <para>To restore the entire archive use:</para> - - <screen>&prompt.root; <userinput>tar Mxvf /dev/fd0</userinput></screen> - - <para>There are two methods to restore only specific files. The - first is to insert the first floppy and use:</para> - - <screen>&prompt.root; <userinput>tar Mxvf /dev/fd0 <replaceable>filename</replaceable></userinput></screen> - - <para>&man.tar.1; will prompt to insert subsequent floppies - until it finds the required file.</para> - - <para>Alternatively, if the floppy containing the file is known, - insert that floppy and use the same command. If the first - file on the floppy is a continuation from the previous one, - &man.tar.1; will warn that it cannot restore it, even if you - have not asked it to.</para> - </sect2> - </sect1> - <sect1 id="backup-strategies"> <sect1info> <authorgroup> @@ -2476,7 +2026,7 @@ cd0: Attempt to query device size failed <note> <para>Livefs CD images are not available for &os; &rel.current;-RELEASE and later. In addition to - the CDROM installation images, flash drive installation + the CD-ROM installation images, flash drive installation images may be used to recover a system. The <quote>memstick</quote> image for &os;/&arch.i386; &rel.current;-RELEASE is available @@ -2517,10 +2067,10 @@ cd0: Attempt to query device size failed <quote>livefs</quote> CD and boot the computer. The original install menu will be displayed on the screen. Select the correct country, then choose - <guimenuitem>Fixit -- Repair mode with CDROM/DVD/floppy or + <guimenuitem>Fixit -- Repair mode with CD-ROM/DVD/floppy or start a shell.</guimenuitem> then select - <guimenuitem>CDROM/DVD -- Use the live filesystem - CDROM/DVD</guimenuitem>. + <guimenuitem>CD-ROM/DVD -- Use the live filesystem + CD-ROM/DVD</guimenuitem>. <command>restore</command> and the other needed programs are located in <filename class="directory">/mnt2/rescue</filename>.</para>
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