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diff --git a/en_US.ISO8859-1/books/handbook/disks/chapter.sgml b/en_US.ISO8859-1/books/handbook/disks/chapter.sgml deleted file mode 100644 index 8c7fbe0e3c..0000000000 --- a/en_US.ISO8859-1/books/handbook/disks/chapter.sgml +++ /dev/null @@ -1,883 +0,0 @@ -<!-- - The FreeBSD Documentation Project - - $FreeBSD: doc/en_US.ISO_8859-1/books/handbook/disks/chapter.sgml,v 1.20 2000/06/13 18:05:39 jim Exp $ ---> - -<chapter id="disks"> - <title>Disks</title> - - <sect1 id="disks-synopsis"> - <title>Synopsis</title> - - <para>This chapter covers how to use disks, whether physical, - memory, or networked, on FreeBSD.</para> - </sect1> - - <sect1 id="disks-bios-numbering"> - <title>BIOS Drive Numbering</title> - - <para>Before you install and configure FreeBSD on your system, there is an - important subject that you should be aware of if, especially if you have - multiple hard drives.</para> - - <para>In a PC running DOS or any of the BIOS-dependent operating systems - (WINxxx), the BIOS is able to abstract the normal disk drive order, and - the operating system goes along with the change. This allows the user - to boot from a disk drive other than the so-called <quote>primary - master</quote>. This is especially convenient for some users who have - found that the simplest and cheapest way to keep a system backup is to - buy an identical second hard drive, and perform routine copies of the - first drive to the second drive using Ghost or XCOPY. Then, if the - first drive fails, or is attacked by a virus, or is scribbled upon by an - operating system defect, he can easily recover by instructing the BIOS - to logically swap the drives. It's like switching the cables on the - drives, but without having to open the case.</para> - - <para>More expensive systems with SCSI controllers often include BIOS - extensions which allow the SCSI drives to be re-ordered in a similar - fashion for up to seven drives.</para> - - <para>A user who is accustomed to taking advantage of these features may - become surprised when the results with FreeBSD are not as expected. - FreeBSD does not use the BIOS, and does not know the <quote>logical BIOS - drive mapping</quote>. This can lead to very perplexing situations, - especially when drives are physically identical in geometry, and have - also been made as data clones of one another.</para> - - <para>When using FreeBSD, always restore the BIOS to natural drive - numbering before installing FreeBSD, and then leave it that way. If you - need to switch drives around, then do so, but do it the hard way, and - open the case and move the jumpers and cables.</para> - - <sidebar> - <title>An illustration from the files of Bill and Fred's Exceptional - Adventures:</title> - - <para>Bill breaks-down an older Wintel box to make another FreeBSD box - for Fred. Bill installs a single SCSI drive as SCSI unit zero, and - installs FreeBSD on it.</para> - - <para>Fred begins using the system, but after several days notices that - the older SCSI drive is reporting numerous soft errors, and reports - this fact to Bill.</para> - - <para>After several more days, Bill decides it's time to address the - situation, so he grabs an identical SCSI drive from the disk drive - "archive" in the back room. An initial surface scan indicates that - this drive is functioning well, so Bill installs this drive as SCSI - unit four, and makes an image copy from drive zero to drive four. Now - that the new drive is installed and functioning nicely, Bill decides - that it's a good idea to start using it, so he uses features in the - SCSI BIOS to re-order the disk drives so that the system boots from - SCSI unit four. FreeBSD boots and runs just fine.</para> - - <para>Fred continues his work for several days, and soon Bill and Fred - decide that it's time for a new adventure -- time to upgrade to a - newer version of FreeBSD. Bill removes SCSI unit zero because it was - a bit flaky, and replaces it with another identical disk drive from - the "archive." Bill then installs the new version of FreeBSD onto the - new SCSI unit zero using Fred's magic internet FTP floppies. The - installation goes well.</para> - - <para>Fred uses the new version of FreeBSD for a few days, and certifies - that it is good enough for use in the engineering department...it's - time to copy all of his work from the old version. So Fred mounts - SCSI unit four (the latest copy of the older FreeBSD version). Fred - is dismayed to find that none of his precious work is present on SCSI - unit four.</para> - - <para>Where did the data go?</para> - - <para>When Bill made an image copy of the original SCSI unit zero onto - SCSI unit four, unit four became the "new clone," When Bill - re-ordered the SCSI BIOS so that he could boot from SCSI unit four, he - was only fooling himself. FreeBSD was still running on SCSI unit zero. - Making this kind of BIOS change will cause some or all of the Boot and - Loader code to be fetched from the selected BIOS drive, but when the - FreeBSD kernel drivers take-over, the BIOS drive numbering will be - ignored, and FreeBSD will transition back to normal drive numbering. - In the illustration at hand, the system continued to operate on the - original SCSI unit zero, and all of Fred's data was there, not on SCSI - unit four. The fact that the system appeared to be running on SCSI - unit four was simply an artifact of human expectations.</para> - - <para>We are delighted to mention that no data bytes were killed or - harmed in any way by our discovery of this phenomenon. The older SCSI - unit zero was retrieved from the bone pile, and all of Fred's work was - returned to him, (and now Bill knows that he can count as high as - zero).</para> - - <para>Although SCSI drives were used in this illustration, the concepts - apply equally to IDE drives.</para> - </sidebar> - </sect1> - - <sect1 id="disks-naming"> - <title>Disk Naming</title> - - <para>Physical drives come in two main flavors, - <acronym>IDE</acronym>, or <acronym>SCSI</acronym>; but there - are also drives backed by RAID controllers, flash memory, and so - forth. Since these behave quite differently, they have their - own drivers and devices.</para> - - <table id="disk-naming-physical-table"> - <title>Physical Disk Naming Conventions</title> - - <tgroup cols="2"> - <thead> - <row> - <entry>Drive type</entry> - <entry>Drive device name</entry> - </row> - </thead> - <tbody> - <row> - <entry>IDE hard drives</entry> - <entry><literal>ad</literal> in 4.0-RELEASE, - <literal>wd</literal> before 4.0-RELEASE.</entry> - </row> - <row> - <entry>IDE CDROM drives</entry> - <entry><literal>acd</literal> in 3.1-RELEASE, - <literal>wcd</literal> before 4.0-RELEASE.</entry> - </row> - <row> - <entry>SCSI hard drives</entry> - <entry><literal>da</literal> from 3.0-RELEASE, - <literal>sd</literal> before 3.0-RELEASE.</entry> - </row> - <row> - <entry>SCSI CDROM drives</entry> - <entry><literal>cd</literal></entry> - </row> - <row> - <entry>Assorted non-standard CDROM drives</entry> - <entry><literal>mcd</literal> for Mitsumi CD-ROM, - <literal>scd</literal> for Sony CD-ROM, - <literal>matcd</literal> for Matsushita/Panasonic CD-ROM - </entry> - </row> - <row> - <entry>Floppy drives</entry> - <entry><literal>fd</literal></entry> - </row> - <row> - <entry>SCSI tape drives</entry> - <entry><literal>sa</literal> from 3.0-RELEASE, - <literal>st</literal> before 3.0-RELEASE.</entry> - </row> - <row> - <entry>IDE tape drives</entry> - <entry><literal>ast</literal> from 4.0-RELEASE, - <literal>wst</literal> before 4.0-RELEASE.</entry> - </row> - <row> - <entry>Flash drives</entry> - <entry><literal>fla</literal> for DiskOnChip Flash device - from 3.3-RELEASE.</entry> - </row> - <row> - <entry>RAID drives</entry> - <entry><literal>myxd</literal> for Mylex, and - <literal>amrd</literal> for AMI MegaRAID, - <literal>idad</literal> for Compaq Smart RAID. - from 4.0-RELEASE. <literal>id</literal> between - 3.2-RELEASE and 4.0-RELEASE.</entry> - </row> - </tbody> - </tgroup> - </table> - - <sect2> - <title>Slices and Partitions</title> - - <para>Physical disks usually contain - <firstterm>slices</firstterm>, unless they are - <quote>dangerously dedicated</quote>. Slice numbers follow - the device name, prefixed with an <literal>s</literal>: - <quote>da0<emphasis>s1</emphasis></quote>.</para> - - <para>Slices, <quote>dangerously dedicated</quote> physical - drives, and other drives contain - <firstterm>partitions</firstterm>, which represented as - letters from <literal>a</literal> to <literal>h</literal>. - <literal>b</literal> is reserved for swap partitions, and - <literal>c</literal> is an unused partition the size of the - entire slice or drive. This is explained in <xref - linkend="disks-adding" />.</para> - </sect2> - </sect1> - - <sect1 id="disks-mounting"> - <title>Mounting and Unmounting Filesystems</title> - - <para>The filesystem is best visualized as a tree, - rooted, as it were, at <filename>/</filename>. - <filename>/dev</filename>, <filename>/usr</filename>, and the - other directories in the root directory are branches, which may - have their own branches, such as - <filename>/usr/local</filename>, and so on.</para> - - <para>There are various reasons to house certain of these - directories on separate filesystems. <filename>/var</filename> - contains log, spool, and various types of temporary files, and - as such, may get filled up. Filling up the root filesystem - isn't a good idea, so splitting <filename>/var</filename> from - <filename>/</filename> is often a good idea.</para> - - <para>Another common reason to contain certain directory trees on - other filesystems is if they are to be housed on separate - physical disks, or are separate virtual disks, such as <link - linkend="nfs">Network File System</link> mounts, or CDROM - drives.</para> - - <sect2 id="disks-fstab"> - <title>The fstab File</title> - - <para>During the <link linkend="boot">boot process</link>, - filesystems listed in <filename>/etc/fstab</filename> are - automatically mounted (unless they are listed with - <option>noauto</option>).</para> - - <para>The <filename>/etc/fstab</filename> file contains a list - of lines of the following format:</para> - - <programlisting><replaceable>device</replaceable> <replaceable>/mount-point</replaceable> <replaceable>fstype</replaceable> <replaceable>options</replaceable> <replaceable>dumpfreq</replaceable> <replaceable>passno</replaceable></programlisting> - - <para><literal>device</literal> is a device name (which should - exist), as explained in the <link linkend="disks-naming">Disk - naming conventions</link> above.</para> - - <para><literal>mount-point</literal> is a directory (which - should exist), on which to mount the filesystem.</para> - - <para><literal>fstype</literal> is the filesystem type to pass - to &man.mount.8;. The default FreeBSD filesystem is - <literal>ufs</literal>.</para> - - <para><literal>options</literal> is either <option>rw</option> - for read-write filesystems, or <option>ro</option> for - read-only filesystems, followed by any other options that may - be needed. A common option is <option>noauto</option> for - filesystems not normally mounted during the boot sequence. - Other options in the &man.mount.8; manual page.</para> - - <para><literal>dumpfreq</literal> is the number of days the - filesystem should be dumped, and <literal>passno</literal> is - the pass number during which the filesystem is mounted during - the boot sequence.</para> - </sect2> - - <sect2 id="disks-mount"> - <title>The mount Command</title> - - <para>The &man.mount.8; command is what is ultimately used to - mount filesystems.</para> - - <para>In its most basic form, you use:</para> - - <informalexample> - <screen>&prompt.root; <userinput>mount <replaceable>device</replaceable> <replaceable>mountpoint</replaceable></userinput></screen> - </informalexample> - - <para>There are plenty of options, as mentioned in the - &man.mount.8; manual page, but the most common are:</para> - - <variablelist> - <title>mount options</title> - - <varlistentry> - <term><option>-a</option></term> - - <listitem> - <para>Mount all filesystems in - <filename>/etc/fstab</filename>, as modified by - <option>-t</option>, if given.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>-d</option></term> - - <listitem> - <para>Do everything but actually mount the - filesystem.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>-f</option></term> - - <listitem> - <para>Force the mounting the filesystem.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>-r</option></term> - - <listitem> - <para>Mount the filesystem read-only.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>-t</option> - <replaceable>fstype</replaceable></term> - - <listitem> - <para>Mount the given filesystem as the given filesystem - type, or mount only filesystems of the given type, if - given the <option>-a</option> option.</para> - - <para><quote>ufs</quote> is the default filesystem - type.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>-u</option></term> - - <listitem> - <para>Update mount options on the filesystem.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>-v</option></term> - - <listitem> - <para>Be verbose.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term><option>-w</option></term> - - <listitem> - <para>Mount the filesystem read-write.</para> - </listitem> - </varlistentry> - </variablelist> - - <para>The <option>-o</option> takes a comma-separated list of - the options, including the following:</para> - - <variablelist> - <varlistentry> - <term>nodev</term> - - <listitem> - <para>Do not interpret special devices on the - filesystem. Useful security option.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term>noexec</term> - - <listitem> - <para>Do not allow execution of binaries on this - filesystem. Useful security option.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term>nosuid</term> - - <listitem> - <para>Do not interpret setuid or setgid flags on the - filesystem. Useful security option.</para> - </listitem> - </varlistentry> - </variablelist> - </sect2> - - <sect2 id="disks-umount"> - <title>The umount Command</title> - - <para>The umount command takes, as a parameter, one of a - mountpoint, a device name, or the <option>-a</option> or - <option>-A</option> option.</para> - - <para>All forms take <option>-f</option> to force unmounting, - and <option>-v</option> for verbosity.</para> - - <para><option>-a</option> and <option>-A</option> are used to - unmount all mounted filesystems, possibly modified by the - filesystem types listed after <option>-t</option>. - <option>-A</option>, however, doesn't attempt to unmount the - root filesystem.</para> - </sect2> - </sect1> - - <sect1 id="disks-adding"> - <title>Adding Disks</title> - - <para><emphasis>Originally contributed by &a.obrien; 26 April - 1998</emphasis></para> - - <para>Lets say we want to add a new SCSI disk to a machine that currently - only has a single drive. First turn off the computer and install the - drive in the computer following the instructions of the computer, - controller, and drive manufacturer. Due the wide variations of procedures - to do this, the details are beyond the scope of this document.</para> - - <para>Login as user <username>root</username>. After you've installed the - drive, inspect <filename>/var/run/dmesg.boot</filename> to ensure the new - disk was found. Continuing with our example, the newly added drive will - be <filename>da1</filename> and we want to mount it on - <filename>/1</filename> (if you are adding an IDE drive, it will - be <filename>wd1</filename> in pre-4.0 systems, or - <filename>ad1</filename> in most 4.X systems).</para> - - <para>Because FreeBSD runs on IBM-PC compatible computers, it must take into - account the PC BIOS partitions. These are different from the traditional - BSD partitions. A PC disk has up to four BIOS partition entries. If the - disk is going to be truly dedicated to FreeBSD, you can use the - <emphasis>dedicated</emphasis> mode. Otherwise, FreeBSD will have to live - with in one of the PC BIOS partitions. FreeBSD calls the PC BIOS - partitions, <emphasis>slices</emphasis> so as not to confuse them with - traditional BSD partitions. You may also use slices on a disk that is - dedicated to FreeBSD, but used in a computer that also has another - operating system installed. This is to not confuse the - <command>fdisk</command> utility of the other operating system.</para> - - <para>In the slice case the drive will be added as - <filename>/dev/da1s1e</filename>. This is read as: SCSI disk, unit number - 1 (second SCSI disk), slice 1 (PC BIOS partition 1), and - <filename>e</filename> BSD partition. In the dedicated case, the drive - will be added simply as <filename>/dev/da1e</filename>.</para> - - <sect2> - <title>Using sysinstall</title> - - <para>You may use <command>/stand/sysinstall</command> to partition and - label a new disk using its easy to use menus. Either login as user - <username>root</username> or use the <command>su</command> command. Run - <command>/stand/sysinstall</command> and enter the - <literal>Configure</literal> menu. With in the <literal>FreeBSD - Configuration Menu</literal>, scroll down and select the - <literal>Partition</literal> item. Next you should be presented with a - list of hard drives installed in your system. If you do not see - <literal>da1</literal> listed, you need to recheck your physical - installation and <command>dmesg</command> output in the file - <filename>/var/run/dmesg.boot</filename>.</para> - - <para>Select <literal>da1</literal> to enter the <literal>FDISK Partition - Editor</literal>. Choose <literal>A</literal> to use the entire disk - for FreeBSD. When asked if you want to <quote>remain cooperative with - any future possible operating systems</quote>, answer - <literal>YES</literal>. Write the changes to the disk using - <command>W</command>. Now exit the FDISK editor using - <command>q</command>. Next you will be asked about the Master Boot - Record. Since you are adding a disk to an already running system, - choose <literal>None</literal>.</para> - - <para>Next enter the <literal>Disk Label Editor</literal>. This is where - you will create the traditional BSD partitions. A disk can have up to - eight partitions, labeled a-h. A few of the partition labels have - special uses. The <literal>a</literal> partition is used for the root - partition (<filename>/</filename>). Thus only your system disk (e.g, - the disk you boot from) should have an <literal>a</literal> partition. - The <literal>b</literal> partition is used for swap partitions, and you - may have many disks with swap partitions. The <literal>c</literal> - partition addresses the entire disk in dedicated mode, or the entire - FreeBSD slice in slice mode. The other partitions are for general - use.</para> - - <para>Sysinstall's Label editor favors the <literal>e</literal> partition - for non-root, non-swap partitions. With in the Label editor, create a - single file system using <command>C</command>. When prompted if this - will be a FS (file system) or swap, choose <literal>FS</literal> and - give a mount point (e.g, <filename>/mnt</filename>). When adding a disk - in post-install mode, Sysinstall will not create entries in - <filename>/etc/fstab</filename> for you, so the mount point you specify - isn't important.</para> - - <para>You are now ready to write the new label to the disk and create a - file system on it. Do this by hitting <command>W</command>. Ignore any - errors from Sysinstall that it could not mount the new partition. Exit - the Label Editor and Sysinstall completely.</para> - - <para>The last step is to edit <filename>/etc/fstab</filename> to add an - entry for your new disk.</para> - </sect2> - - <sect2> - <title>Using Command Line Utilities</title> - - <sect3> - <title>* Using Slices</title> - - <para></para> - </sect3> - - <sect3> - <title>Dedicated</title> - - <para>If you will not be sharing the new drive with another operating - system, you may use the <literal>dedicated</literal> mode. Remember - this mode can confuse Microsoft operating systems; however, no damage - will be done by them. IBM's OS/2 however, will - <quote>appropriate</quote> any partition it finds which it doesn't - understand.</para> - - <screen>&prompt.root; <userinput>dd if=/dev/zero of=/dev/rda1 bs=1k count=1</userinput> -&prompt.root; <userinput>disklabel -Brw da1 auto</userinput> -&prompt.root; <userinput>disklabel -e da1</userinput> # create the `e' partition -&prompt.root; <userinput>newfs -d0 /dev/rda1e</userinput> -&prompt.root; <userinput>mkdir -p /1</userinput> -&prompt.root; <userinput>vi /etc/fstab</userinput> # add an entry for /dev/da1e -&prompt.root; <userinput>mount /1</userinput></screen> - - <para>An alternate method is:</para> - - <screen>&prompt.root; <userinput>dd if=/dev/zero of=/dev/rda1 count=2</userinput> -&prompt.root; <userinput>disklabel /dev/rda1 | disklabel -BrR da1 /dev/stdin</userinput> -&prompt.root; <userinput>newfs /dev/rda1e</userinput> -&prompt.root; <userinput>mkdir -p /1</userinput> -&prompt.root; <userinput>vi /etc/fstab</userinput> # add an entry for /dev/da1e -&prompt.root; <userinput>mount /1</userinput></screen> - </sect3> - </sect2> - </sect1> - - <sect1 id="disks-virtual"> - <title>Virtual Disks: Network, Memory, and File-Based Filesystems</title> - - <para>Besides the disks you physically insert into your computer; - floppies, CDs, hard drives, and so forth, other forms of disks - are understood by FreeBSD - the <firstterm>virtual - disks</firstterm>.</para> - - <para>These include network filesystems such as the <link - linkend="nfs">Network Filesystem</link> and Coda, memory-based - filesystems such as <link linkend="disks-md">md</link> and - file-backed filesystems created by <link - linkend="disks-vnconfig">vnconfig</link>.</para> - - <sect2 id="disks-vnconfig"> - <title>vnconfig: file-backed filesystem</title> - - <para>&man.vnconfig.8; configures and enables vnode pseudo disk - devices. A <firstterm>vnode</firstterm> is a representation - of a file, and is the focus of file activity. This means that - &man.vnconfig.8; uses files to create and operate a - filesystem. One possible use is the mounting of floppy or CD - images kept in files.</para> - - <para>To mount an existing filesystem image:</para> - - <example> - <title>Using vnconfig to mount an existing filesystem - image</title> - - <screen>&prompt.root; <userinput>vnconfig vn<replaceable>0</replaceable> <replaceable>diskimage</replaceable></userinput> -&prompt.root; <userinput>mount /dev/vn<replaceable>0</replaceable>c <replaceable>/mnt</replaceable></userinput></screen> - </example> - - <para>To create a new filesystem image with vnconfig:</para> - - <example> - <title>Creating a New File-Backed Disk with vnconfig</title> - - <screen>&prompt.root; <userinput>dd if=/dev/zero of=<replaceable>newimage</replaceable> bs=1k count=<replaceable>5</replaceable>k</userinput> -5120+0 records in -5120+0 records out -&prompt.root; <userinput>vnconfig -s labels -c vn<replaceable>0</replaceable> <replaceable>newimage</replaceable></userinput> -&prompt.root; <userinput>disklabel -r -w vn<replaceable>0</replaceable> auto</userinput> -&prompt.root; <userinput>newfs vn<replaceable>0</replaceable>c</userinput> -Warning: 2048 sector(s) in last cylinder unallocated -/dev/rvn0c: 10240 sectors in 3 cylinders of 1 tracks, 4096 sectors - 5.0MB in 1 cyl groups (16 c/g, 32.00MB/g, 1280 i/g) -super-block backups (for fsck -b #) at: - 32 -&prompt.root; <userinput>mount /dev/vn<replaceable>0</replaceable>c <replaceable>/mnt</replaceable></userinput> -&prompt.root; <userinput>df <replaceable>/mnt</replaceable></userinput> -Filesystem 1K-blocks Used Avail Capacity Mounted on -/dev/vn0c 4927 1 4532 0% /mnt</screen> - </example> - </sect2> - - <sect2 id="disks-md"> - <title>md: Memory Filesystem</title> - - <para>md is a simple, efficient means to do memory - filesystems.</para> - - <para>Simply take a filesystem you've prepared with, for - example, &man.vnconfig.8;, and:</para> - - <example> - <title>md memory disk</title> - - <screen>&prompt.root; <userinput>dd if=<replaceable>newimage</replaceable> of=/dev/md<replaceable>0</replaceable></userinput> -5120+0 records in -5120+0 records out -&prompt.root; <userinput>mount /dev/md<replaceable>0c</replaceable> <replaceable>/mnt</replaceable></userinput> -&prompt.root; <userinput>df <replaceable>/mnt</replaceable></userinput> -Filesystem 1K-blocks Used Avail Capacity Mounted on -/dev/md0c 4927 1 4532 0% /mnt</screen> - </example> - </sect2> - </sect1> - - <sect1 id="quotas"> - <title>Disk Quotas</title> - - <para>Quotas are an optional feature of the operating system that - allow you to limit the amount of disk space and/or the number of - files a user, or members of a group, may allocate on a per-file - system basis. This is used most often on timesharing systems where - it is desirable to limit the amount of resources any one user or - group of users may allocate. This will prevent one user from - consuming all of the available disk space.</para> - - <sect2> - <title>Configuring Your System to Enable Disk Quotas</title> - - <para>Before attempting to use disk quotas it is necessary to make - sure that quotas are configured in your kernel. This is done by - adding the following line to your kernel configuration - file:</para> - - <programlisting> -options QUOTA</programlisting> - - <para>The stock <filename>GENERIC</filename> kernel does not have - this enabled by default, so you will have to configure, build and - install a custom kernel in order to use disk quotas. Please refer - to the <link linkend="kernelconfig">Configuring the FreeBSD - Kernel</link> section for more information on kernel - configuration.</para> - - <para>Next you will need to enable disk quotas in - <filename>/etc/rc.conf</filename>. This is done by adding the - line:</para> - - <programlisting> -enable_quotas=<quote>YES</quote></programlisting> - - <para>For finer control over your quota startup, there is an - additional configuration variable available. Normally on bootup, - the quota integrity of each file system is checked by the - <command>quotacheck</command> program. The - <command>quotacheck</command> facility insures that the data in - the quota database properly reflects the data on the file system. - This is a very time consuming process that will significantly - affect the time your system takes to boot. If you would like to - skip this step, a variable is made available for the - purpose:</para> - - <programlisting> -check_quotas=<quote>NO</quote></programlisting> - - <para>If you are running FreeBSD prior to 3.2-RELEASE, the - configuration is simpler, and consists of only one variable. Set - the following in your <filename>/etc/rc.conf</filename>:</para> - - <programlisting> -check_quotas=<quote>YES</quote></programlisting> - - <para>Finally you will need to edit <filename>/etc/fstab</filename> - to enable disk quotas on a per-file system basis. This is where - you can either enable user or group quotas or both for all of your - file systems.</para> - - <para>To enable per-user quotas on a file system, add the - <literal>userquota</literal> option to the options field in the - <filename>/etc/fstab</filename> entry for the file system you want - to to enable quotas on. For example:</para> - - <programlisting> -/dev/da1s2g /home ufs rw,userquota 1 2</programlisting> - - <para>Similarly, to enable group quotas, use the - <literal>groupquota</literal> option instead of the - <literal>userquota</literal> keyword. To enable both user and - group quotas, change the entry as follows:</para> - - <programlisting> -/dev/da1s2g /home ufs rw,userquota,groupquota 1 2</programlisting> - - <para>By default the quota files are stored in the root directory of - the file system with the names <filename>quota.user</filename> and - <filename>quota.group</filename> for user and group quotas - respectively. See <command>man fstab</command> for more - information. Even though that man page says that you can specify - an alternate location for the quota files, this is not recommended - because the various quota utilities do not seem to handle this - properly.</para> - - <para>At this point you should reboot your system with your new - kernel. <filename>/etc/rc</filename> will automatically run the - appropriate commands to create the initial quota files for all of - the quotas you enabled in <filename>/etc/fstab</filename>, so - there is no need to manually create any zero length quota - files.</para> - - <para>In the normal course of operations you should not be required - to run the <command>quotacheck</command>, - <command>quotaon</command>, or <command>quotaoff</command> - commands manually. However, you may want to read their man pages - just to be familiar with their operation.</para> - </sect2> - - <sect2> - <title>Setting Quota Limits</title> - - <para>Once you have configured your system to enable quotas, verify - that they really are enabled. An easy way to do this is to - run:</para> - - <screen>&prompt.root; <userinput>quota -v</userinput></screen> - - <para>You should see a one line summary of disk usage and current - quota limits for each file system that quotas are enabled - on.</para> - - <para>You are now ready to start assigning quota limits with the - <command>edquota</command> command.</para> - - <para>You have several options on how to enforce limits on the - amount of disk space a user or group may allocate, and how many - files they may create. You may limit allocations based on disk - space (block quotas) or number of files (inode quotas) or a - combination of both. Each of these limits are further broken down - into two categories; hard and soft limits.</para> - - <para>A hard limit may not be exceeded. Once a user reaches their - hard limit they may not make any further allocations on the file - system in question. For example, if the user has a hard limit of - 500 blocks on a file system and is currently using 490 blocks, the - user can only allocate an additional 10 blocks. Attempting to - allocate an additional 11 blocks will fail.</para> - - <para>Soft limits on the other hand can be exceeded for a limited - amount of time. This period of time is known as the grace period, - which is one week by default. If a user stays over his or her - soft limit longer than their grace period, the soft limit will - turn into a hard limit and no further allocations will be allowed. - When the user drops back below the soft limit, the grace period - will be reset.</para> - - <para>The following is an example of what you might see when you run - the <command>edquota</command> command. When the - <command>edquota</command> command is invoked, you are placed into - the editor specified by the <envar>EDITOR</envar> environment - variable, or in the <command>vi</command> editor if the - <envar>EDITOR</envar> variable is not set, to allow you to edit - the quota limits.</para> - - <screen>&prompt.root; <userinput>edquota -u test</userinput></screen> - - <programlisting> -Quotas for user test: -/usr: blocks in use: 65, limits (soft = 50, hard = 75) - inodes in use: 7, limits (soft = 50, hard = 60) -/usr/var: blocks in use: 0, limits (soft = 50, hard = 75) - inodes in use: 0, limits (soft = 50, hard = 60)</programlisting> - - <para>You will normally see two lines for each file system that has - quotas enabled. One line for the block limits, and one line for - inode limits. Simply change the value you want updated to modify - the quota limit. For example, to raise this users block limit - from a soft limit of 50 and a hard limit of 75 to a soft limit of - 500 and a hard limit of 600, change:</para> - - <programlisting>/usr: blocks in use: 65, limits (soft = 50, hard = 75)</programlisting> - - <para>to:</para> - - <programlisting> /usr: blocks in use: 65, limits (soft = 500, hard = 600)</programlisting> - - <para>The new quota limits will be in place when you exit the - editor.</para> - - <para>Sometimes it is desirable to set quota limits on a range of - uids. This can be done by use of the <option>-p</option> option - on the <command>edquota</command> command. First, assign the - desired quota limit to a user, and then run - <command>edquota -p protouser startuid-enduid</command>. For - example, if user <username>test</username> has the desired quota - limits, the following command can be used to duplicate those quota - limits for uids 10,000 through 19,999:</para> - - <screen>&prompt.root; <userinput>edquota -p test 10000-19999</userinput></screen> - - <para>See <command>man edquota</command> for more detailed - information.</para> - </sect2> - - <sect2> - <title>Checking Quota Limits and Disk Usage</title> - - <para>You can use either the <command>quota</command> or the - <command>repquota</command> commands to check quota limits and - disk usage. The <command>quota</command> command can be used to - check individual user and group quotas and disk usage. Only the - super-user may examine quotas and usage for other users, or for - groups that they are not a member of. The - <command>repquota</command> command can be used to get a summary - of all quotas and disk usage for file systems with quotas - enabled.</para> - - <para>The following is some sample output from the - <command>quota -v</command> command for a user that has quota - limits on two file systems.</para> - - <programlisting> -Disk quotas for user test (uid 1002): - Filesystem blocks quota limit grace files quota limit grace - /usr 65* 50 75 5days 7 50 60 - /usr/var 0 50 75 0 50 60</programlisting> - - <para>On the <filename>/usr</filename> file system in the above - example this user is currently 15 blocks over their soft limit of - 50 blocks and has 5 days of their grace period left. Note the - asterisk <literal>*</literal> which indicates that the user is - currently over their quota limit.</para> - - <para>Normally file systems that the user is not using any disk - space on will not show up in the output from the - <command>quota</command> command, even if they have a quota limit - assigned for that file system. The <option>-v</option> option - will display those file systems, such as the - <filename>/usr/var</filename> file system in the above - example.</para> - </sect2> - - <sect2> - <title>Quotas over NFS</title> - - <para>Quotas are enforced by the quota subsystem on the NFS server. - The &man.rpc.rquotad.8; daemon makes quota information available - to the &man.quota.1; command on NFS clients, allowing users on - those machines to see their quota statistics.</para> - - <para>Enable <command>rpc.rquotad</command> in - <filename>/etc/inetd.conf</filename> like so:</para> - - <programlisting> -rquotad/1 dgram rpc/udp wait root /usr/libexec/rpc.rquotad rpc.rquotad</programlisting> - - <para>Now restart <command>inetd</command>:</para> - - <screen>&prompt.root; <userinput>kill -HUP `cat /var/run/inetd.pid`</userinput></screen> - </sect2> - </sect1> -</chapter> - -<!-- - Local Variables: - mode: sgml - sgml-declaration: "../chapter.decl" - sgml-indent-data: t - sgml-omittag: nil - sgml-always-quote-attributes: t - sgml-parent-document: ("../book.sgml" "part" "chapter") - End: ---> |