bcf62d4c42
An an aside, most of this part of the chapter is marked up incorrectly--e.g., <quote> is used where something like <devicename> is much more appropriate. This delta doesn't help, but keeps things relatively consistent. PR: 30062 Submitted by: Mike Meyer <mwm@mired.org>
1536 lines
62 KiB
Text
1536 lines
62 KiB
Text
<!--
|
|
The FreeBSD Documentation Project
|
|
|
|
$FreeBSD: doc/en_US.ISO8859-1/books/handbook/disks/chapter.sgml,v 1.56 2001/08/24 20:44:08 chern Exp $
|
|
-->
|
|
|
|
<chapter id="disks">
|
|
<title>Disks</title>
|
|
|
|
<sect1 id="disks-synopsis">
|
|
<title>Synopsis</title>
|
|
|
|
|
|
<para>This chapter covers the use of disks in FreeBSD. This
|
|
includes memory-backed disks, network-attached disks, and
|
|
standard SCSI/IDE storage devices.</para>
|
|
|
|
<para>After reading this chapter you will know:</para>
|
|
<itemizedlist>
|
|
<listitem><para>The terminology FreeBSD uses to describe the
|
|
organization of data on a physical disk (partitions and slices).</para>
|
|
</listitem>
|
|
<listitem><para>How to mount and unmount filesystems.</para>
|
|
</listitem>
|
|
<listitem><para>How to add additional hard disks to your system.</para>
|
|
</listitem>
|
|
<listitem><para>How to setup virtual filesystems, such as memory
|
|
disks.</para></listitem>
|
|
<listitem>
|
|
<para>How to use quotas to limit disk space usage.</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>How to create and burn CDs and DVDs on FreeBSD.</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
</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, especially if you have
|
|
multiple hard drives.</para>
|
|
|
|
<indexterm><primary>DOS</primary></indexterm>
|
|
<indexterm><primary>Microsoft Windows</primary></indexterm>
|
|
<para>In a PC running a BIOS-dependent operating system such as
|
|
MS-DOS or Microsoft Windows, 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
|
|
<application>Ghost</application> or <application>XCOPY</application>
|
|
. 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 is like switching the cables on the
|
|
drives, but without having to open the case.</para>
|
|
|
|
<indexterm><primary>SCSI</primary></indexterm>
|
|
<indexterm><primary>BIOS</primary></indexterm>
|
|
<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 is 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 is 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 is 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 is
|
|
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>
|
|
|
|
<indexterm><primary>IDE</primary></indexterm>
|
|
<indexterm><primary>SCSI</primary></indexterm>
|
|
<indexterm><primary>RAID</primary></indexterm>
|
|
<indexterm><primary>flash memory</primary></indexterm>
|
|
<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> from 4.0-RELEASE,
|
|
<literal>wcd</literal> before 4.0-RELEASE.</entry>
|
|
</row>
|
|
<row>
|
|
<entry>SCSI hard drives and USB Mass storage devices</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>
|
|
|
|
<para>All the drives attached through a specific driver are
|
|
numbered starting at 0. So the first IDE drive would be
|
|
<quote>ad<emphasis>0</emphasis></quote>. You seldom need to use
|
|
these devices.</para>
|
|
|
|
<sect2 id="slicesandpartitions">
|
|
<title>Slices and Partitions</title>
|
|
<indexterm><primary>slices</primary></indexterm>
|
|
<indexterm><primary>partitions</primary></indexterm>
|
|
<indexterm><primary>dangerously dedicated</primary></indexterm>
|
|
<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>,
|
|
starting at 1. So <quote>da0<emphasis>s1</emphasis></quote>
|
|
is the first slice on the first SCSI drive. There can only be
|
|
four physical slices on a disk, but you can have logical
|
|
slices inside physical slices of the appropriate type. These
|
|
extended slices are numbered starting at 5, so
|
|
<quote>ad0<emphasis>s5</emphasis></quote> is the first
|
|
extended slice on a disk. These devices are used by file
|
|
systems that expect to occupy a slice.</para>
|
|
|
|
<para>Slices, <quote>dangerously dedicated</quote> physical
|
|
drives, and other drives contain
|
|
<firstterm>partitions</firstterm>, which are represented as
|
|
letters from <literal>a</literal> to <literal>h</literal>.
|
|
This letter is appended to the device name, so
|
|
<quote>da0<emphasis>a</emphasis></quote> is the a partition on
|
|
the first da drive, which is <quote>dangerously dedicated</quote>.
|
|
<quote>ad1s3<emphasis>e</emphasis></quote> is the fifth partition
|
|
in the third slice of the second IDE disk drive.</para>
|
|
|
|
<para>The boot code expects partition <literal>a</literal> to be
|
|
the root partition. Partition <literal>b</literal> is normally
|
|
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>
|
|
|
|
<indexterm><primary>root filesystem</primary></indexterm>
|
|
<para>There are various reasons to house some of these
|
|
directories on separate filesystems. <filename>/var</filename>
|
|
contains the directories <filename>log/</filename>,
|
|
<filename>spool/</filename>,
|
|
and various types of temporary files, and
|
|
as such, may get filled up. Filling up the root filesystem
|
|
is not a good idea, so splitting <filename>/var</filename> from
|
|
<filename>/</filename> is often favorable.</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 <filename>fstab</filename> File</title>
|
|
<indexterm>
|
|
<primary>filesystems</primary>
|
|
<secondary>mounted with fstab</secondary>
|
|
</indexterm>
|
|
|
|
<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>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><literal>device</literal></term>
|
|
<listitem>
|
|
<para>A device name (which should exist), as explained in
|
|
the <link linkend="disks-naming">Disk naming
|
|
conventions</link> above.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><literal>mount-point</literal></term>
|
|
|
|
<listitem><para>A directory (which should exist), on which
|
|
to mount the filesystem.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><literal>fstype</literal></term>
|
|
|
|
<listitem><para>The filesystem type to pass to
|
|
&man.mount.8;. The default FreeBSD filesystem is
|
|
<literal>ufs</literal>.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><literal>options</literal></term>
|
|
|
|
<listitem><para>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 are listed in the &man.mount.8; manual page.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><literal>dumpfreq</literal></term>
|
|
|
|
<listitem><para>The number of days the filesystem should be
|
|
dumped, and <literal>passno</literal> is the pass number
|
|
during which the filesystem is checked during the boot
|
|
sequence.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</sect2>
|
|
|
|
<sect2 id="disks-mount">
|
|
<title>The mount Command</title>
|
|
<indexterm>
|
|
<primary>filesystems</primary>
|
|
<secondary>mounting</secondary>
|
|
</indexterm>
|
|
|
|
<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 the filesystems listed in
|
|
<filename>/etc/fstab</filename>. Exceptions are those
|
|
marked as <quote>noauto</quote>, excluded by the
|
|
<option>-t</option> flag, or those that are already
|
|
mounted.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><option>-d</option></term>
|
|
|
|
<listitem>
|
|
<para>Do everything except for the actual system call.
|
|
This option is useful in conjunction with the
|
|
<option>-v</option> flag to determine what the
|
|
<command>mount</command> is actually trying to do.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><option>-f</option></term>
|
|
|
|
<listitem>
|
|
<para>Force the mount of an unclean filesystem
|
|
(dangerous), or forces the revocation of write access
|
|
when downgrading a filesystem's mount status from
|
|
read-write to read-only.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><option>-r</option></term>
|
|
|
|
<listitem>
|
|
<para>Mount the filesystem read-only. This is identical
|
|
to using the <option>rdonly</option> argument to the
|
|
<option>-o</option> option.</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> 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. This is a useful security option.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>noexec</term>
|
|
|
|
<listitem>
|
|
<para>Do not allow execution of binaries on this
|
|
filesystem. This is also a useful security option.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term>nosuid</term>
|
|
|
|
<listitem>
|
|
<para>Do not interpret setuid or setgid flags on the
|
|
filesystem. This is also a useful security option.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</sect2>
|
|
|
|
<sect2 id="disks-umount">
|
|
<title>The <command>umount</command> Command</title>
|
|
<indexterm>
|
|
<primary>filesystems</primary>
|
|
<secondary>unmounting</secondary>
|
|
</indexterm>
|
|
|
|
<para>The &man.umount.8; 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, does not attempt to unmount the
|
|
root filesystem.</para>
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="disks-adding">
|
|
<sect1info>
|
|
<authorgroup>
|
|
<author>
|
|
<firstname>David</firstname>
|
|
<surname>O'Brien</surname>
|
|
<contrib>Originally contributed by </contrib>
|
|
</author>
|
|
</authorgroup>
|
|
<!-- 26 Apr 1998 -->
|
|
</sect1info>
|
|
|
|
<title>Adding Disks</title>
|
|
|
|
<indexterm>
|
|
<primary>disks</primary>
|
|
<secondary>adding</secondary>
|
|
</indexterm>
|
|
|
|
<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 to 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 have 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 <devicename>da1</devicename> and we want to mount it on
|
|
<filename>/1</filename> (if you are adding an IDE drive, the device name
|
|
will be <devicename>wd1</devicename> in pre-4.0 systems, or
|
|
<devicename>ad1</devicename> in most 4.X systems).</para>
|
|
|
|
<indexterm><primary>partitions</primary></indexterm>
|
|
<indexterm><primary>slices</primary></indexterm>
|
|
<indexterm>
|
|
<primary><command>fdisk</command></primary>
|
|
</indexterm>
|
|
|
|
<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 within 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 &man.sysinstall.8;</title>
|
|
<indexterm>
|
|
<primary><application>sysinstall</application></primary>
|
|
<secondary>adding disks</secondary>
|
|
</indexterm>
|
|
<indexterm>
|
|
<primary>su</primary>
|
|
</indexterm>
|
|
<procedure>
|
|
<step>
|
|
<title>Navigating <application>Sysinstall</application></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. Within 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>
|
|
</step>
|
|
|
|
<step>
|
|
<title>FDISK Partition Editor</title>
|
|
<para>Select <literal>da1</literal> to enter the <literal>FDISK
|
|
Partition Editor</literal>. Type <userinput>A</userinput> 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 <userinput>W</userinput>. Now exit the
|
|
FDISK editor by typing <userinput>q</userinput>. 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>
|
|
</step>
|
|
|
|
<step>
|
|
<title>Disk Label Editor</title>
|
|
<indexterm><primary>BSD partitions</primary></indexterm>
|
|
|
|
<para>Next, <application>Sysinstall</application> will
|
|
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
|
|
<literal>a-h</literal>.
|
|
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><application>Sysinstall</application>'s Label editor
|
|
favors the <literal>e</literal>
|
|
partition for non-root, non-swap partitions. Within the
|
|
Label editor, create a single file system by typing
|
|
<userinput>C</userinput>. When prompted if this will be a FS
|
|
(file system) or swap, choose <literal>FS</literal> and type in a
|
|
mount point (e.g, <filename>/mnt</filename>). When adding a
|
|
disk in post-install mode, <application>Sysinstall</application>
|
|
will not create entries
|
|
in <filename>/etc/fstab</filename> for you, so the mount point
|
|
you specify is not 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 typing
|
|
<userinput>W</userinput>. Ignore any errors from
|
|
<application>Sysinstall</application> that
|
|
it could not mount the new partition. Exit the Label Editor
|
|
and <application>Sysinstall</application> completely.</para>
|
|
</step>
|
|
|
|
<step>
|
|
<title>Finish</title>
|
|
|
|
<para>The last step is to edit <filename>/etc/fstab</filename>
|
|
to add an entry for your new disk.</para>
|
|
</step>
|
|
</procedure>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Using Command Line Utilities</title>
|
|
|
|
<sect3>
|
|
<title>Using Slices</title>
|
|
|
|
<para>This setup will allow your disk to work correctly with
|
|
other operating systems that might be installed on your
|
|
computer and will not confuse other operating systems'
|
|
<command>fdisk</command> utilities. It is recommended
|
|
to use this method for new disk installs. Only use
|
|
<literal>dedicated</literal> mode if you have a good reason
|
|
to do so!</para>
|
|
|
|
<screen>&prompt.root; <userinput>dd if=/dev/zero of=/dev/rda1 bs=1k count=1</userinput>
|
|
&prompt.root; <userinput>fdisk -BI da1</userinput> #Initialize your new disk
|
|
&prompt.root; <userinput>disklabel -B -w -r da1s1 auto</userinput> #Label it.
|
|
&prompt.root; <userinput>disklabel -e da1s1</userinput> # Edit the disklabel just created and add any partitions.
|
|
&prompt.root; <userinput>mkdir -p /1</userinput>
|
|
&prompt.root; <userinput>newfs /dev/da1s1e</userinput> # Repeat this for every partition you created.
|
|
&prompt.root; <userinput>mount -t ufs /dev/da1s1e /1</userinput> # Mount the partition(s)
|
|
&prompt.root; <userinput>vi /etc/fstab</userinput> # Add the appropriate entry/entries to your <filename>/etc/fstab</filename>.</screen>
|
|
|
|
<para>If you have an IDE disk, substitute <filename>ad</filename>
|
|
for <filename>da</filename>. On pre-4.X systems use
|
|
<filename>wd</filename>.</para>
|
|
</sect3>
|
|
|
|
<sect3>
|
|
<title>Dedicated</title>
|
|
<indexterm><primary>OS/2</primary></indexterm>
|
|
|
|
<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>
|
|
<indexterm><primary>virtual disks</primary></indexterm>
|
|
<indexterm>
|
|
<primary>disks</primary>
|
|
<secondary>virtual</secondary>
|
|
</indexterm>
|
|
|
|
<para>Aside from 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>
|
|
|
|
<indexterm><primary>NFS</primary></indexterm>
|
|
<indexterm><primary>Coda</primary></indexterm>
|
|
<indexterm>
|
|
<primary>disks</primary>
|
|
<secondary>memory</secondary>
|
|
</indexterm>
|
|
<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> or
|
|
<command>mdconfig</command>.</para>
|
|
|
|
<sect2 id="disks-vnconfig">
|
|
<title>vnconfig: File-Backed Filesystem</title>
|
|
<indexterm>
|
|
<primary>disks</primary>
|
|
<secondary>file-backed</secondary>
|
|
</indexterm>
|
|
|
|
<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>
|
|
<indexterm>
|
|
<primary>disks</primary>
|
|
<secondary>memory filesystem</secondary>
|
|
</indexterm>
|
|
|
|
<para><devicename>md</devicename> is a simple, efficient means to create memory
|
|
filesystems.</para>
|
|
|
|
<para>Simply take a filesystem you have 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>
|
|
<indexterm>
|
|
<primary>accounting</primary>
|
|
<secondary>disk space</secondary>
|
|
</indexterm>
|
|
<indexterm><primary>disk quotas</primary></indexterm>
|
|
|
|
<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 <xref linkend="kernelconfig"> 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>
|
|
<indexterm>
|
|
<primary>disk quotas</primary>
|
|
<secondary>checking</secondary>
|
|
</indexterm>
|
|
<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 in <filename>/etc/rc.conf</filename>
|
|
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 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 &man.fstab.5; for more
|
|
information. Even though the &man.fstab.5; manual 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 manual pages
|
|
just to be familiar with their operation.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Setting Quota Limits</title>
|
|
<indexterm>
|
|
<primary>disk quotas</primary>
|
|
<secondary>limits</secondary>
|
|
</indexterm>
|
|
|
|
<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>
|
|
|
|
<indexterm><primary>hard limit</primary></indexterm>
|
|
<para>A hard limit may not be exceeded. Once a user reaches his
|
|
hard limit he 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>
|
|
|
|
<indexterm><primary>soft limit</primary></indexterm>
|
|
<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 the 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>For more information see &man.edquota.8;.</para>
|
|
</sect2>
|
|
|
|
<sect2>
|
|
<title>Checking Quota Limits and Disk Usage</title>
|
|
<indexterm>
|
|
<primary>disk quotas</primary>
|
|
<secondary>checking</secondary>
|
|
</indexterm>
|
|
|
|
<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>
|
|
|
|
<indexterm><primary>grace period</primary></indexterm>
|
|
<para>On the <filename>/usr</filename> file system in the above
|
|
example this user is currently 15 blocks over the soft limit of
|
|
50 blocks and has 5 days of the grace period left. Note the
|
|
asterisk <literal>*</literal> which indicates that the user is
|
|
currently over his 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 he has 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>
|
|
<indexterm><primary>NFS</primary></indexterm>
|
|
|
|
<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>
|
|
|
|
<sect1 id="creating-cds">
|
|
<sect1info>
|
|
<authorgroup>
|
|
<author>
|
|
<firstname>Mike</firstname>
|
|
<surname>Meyer</surname>
|
|
<contrib>Contributed by </contrib>
|
|
<!-- mwm@mired.org -->
|
|
</author>
|
|
</authorgroup>
|
|
<!-- Apr 2001 -->
|
|
</sect1info>
|
|
|
|
<title>Creating CDs</title>
|
|
<indexterm>
|
|
<primary>CDROMs</primary>
|
|
<secondary>creating</secondary>
|
|
</indexterm>
|
|
|
|
<sect2>
|
|
<title>Introduction</title>
|
|
|
|
<para>CDs have a number of features that differentiate them from
|
|
conventional disks. Initially, they were not writable by the
|
|
user. They are designed so that they can be read continuously without
|
|
delays to move the head between tracks. They are also much easier
|
|
to transport between systems than similarly sized media were at the
|
|
time.</para>
|
|
|
|
<para>CDs do have tracks, but this refers to a section of data to
|
|
be read continuously and not a physical property of the disk. To
|
|
produce a CD on FreeBSD, you prepare the data files that are going
|
|
to make up the tracks on the CD, then write the tracks to the
|
|
CD.</para>
|
|
|
|
<indexterm><primary>ISO 9660</primary></indexterm>
|
|
<indexterm>
|
|
<primary>filesystems</primary>
|
|
<secondary>ISO-9660</secondary>
|
|
</indexterm>
|
|
<para>The ISO 9660 file system was designed to deal with these
|
|
differences. It unfortunately codifies file system limits that were
|
|
common then. Fortunately, it provides an extension mechanism that
|
|
allows properly written CDs to exceed those limits while still
|
|
working with systems that do not support those extensions.</para>
|
|
|
|
<indexterm>
|
|
<primary><command>mkisofs</command></primary>
|
|
</indexterm>
|
|
<para>The <command><link linkend="mkisofs">mkisofs</link></command>
|
|
program is used to produce a data file containing an ISO 9660 file
|
|
system. It has options that support various extensions, and is
|
|
described below. You can install it with the
|
|
<port>sysutils/mkisofs</port> port.</para>
|
|
|
|
<indexterm>
|
|
<primary>CD burner</primary>
|
|
<secondary>ATAPI</secondary>
|
|
</indexterm>
|
|
<para>Which tool to use to burn the CD depends on whether your CD burner
|
|
is ATAPI or something else. ATAPI CD burners use the <command><link
|
|
linkend="burncd">burncd</link></command> program that is part of
|
|
the base system. SCSI and USB CD burners should use
|
|
<command><link linkend="cdrecord">cdrecord</link></command> from
|
|
the <port>sysutils/cdrtools</port> port.</para>
|
|
|
|
<para><command>burncd</command> has a limited number of
|
|
supported drives. To find out if a drive is supported, see
|
|
<ulink url="http://freebsd.dk/ata/">CD-R/RW supported
|
|
drives</ulink>.</para>
|
|
</sect2>
|
|
|
|
<sect2 id="mkisofs">
|
|
<title>mkisofs</title>
|
|
|
|
<para><command>mkisofs</command> produces an ISO 9660 file system
|
|
that is an image of a directory tree in the Unix file system name
|
|
space. The simplest usage is:</para>
|
|
|
|
<screen>&prompt.root; <userinput>mkisofs <option>-o</option> <replaceable>imagefile.iso</replaceable> <replaceable>/path/to/tree</replaceable></userinput></screen>
|
|
|
|
<indexterm>
|
|
<primary>filesystems</primary>
|
|
<secondary>ISO-9660</secondary>
|
|
</indexterm>
|
|
<para>This command will create an <replaceable>imagefile</replaceable>
|
|
containing an ISO 9660 file system that is a copy of the tree at
|
|
<replaceable>/path/to/tree</replaceable>. In the process, it will
|
|
map the file names to names that fit the limitations of the
|
|
standard ISO 9660 file system, and will exclude files that have
|
|
names uncharacteristic of ISO file systems.</para>
|
|
|
|
<indexterm>
|
|
<primary>filesystems</primary>
|
|
<secondary>HFS</secondary>
|
|
</indexterm>
|
|
<indexterm>
|
|
<primary>filesystems</primary>
|
|
<secondary>Joliet</secondary>
|
|
</indexterm>
|
|
<para>A number of options are available to overcome those
|
|
restrictions. In particular, <option>-R</option> enables the
|
|
Rock Ridge extensions common to Unix systems, <option>-J</option>
|
|
enables Joliet extensions used by Microsoft systems, and
|
|
<option>-hfs</option> can be used to create HFS file systems used
|
|
by MacOS.</para>
|
|
|
|
<para>For CDs that are going to be used only on FreeBSD systems,
|
|
<option>-U</option> can be used to disable all filename
|
|
restrictions. When used with <option>-R</option>, it produces a
|
|
file system image that is identical to the FreeBSD tree you started
|
|
from, though it may violate the ISO 9660 standard in a number of
|
|
ways.</para>
|
|
|
|
<indexterm>
|
|
<primary>CDROMs</primary>
|
|
<secondary>creating bootable</secondary>
|
|
</indexterm>
|
|
<para>The last option of general use is <option>-b</option>. This is
|
|
used to specify the location of the boot image for use in producing an
|
|
<quote>El Torito</quote> bootable CD. This option takes an
|
|
argument which is the path to a boot image from the top of the
|
|
tree being written to the CD. So, given that
|
|
<filename>/tmp/myboot</filename> holds a bootable FreeBSD system
|
|
with the boot image in
|
|
<filename>/tmp/myboot/boot/cdboot</filename>, you could produce the
|
|
image of an ISO 9660 file system in
|
|
<filename>/tmp/bootable.iso</filename> like so:</para>
|
|
|
|
<screen>&prompt.root; <userinput>mkisofs <option>-U</option> <option>-R</option> <option>-b</option> <filename>boot/cdboot</filename> <option>-o</option> <filename>/tmp/bootable.iso</filename> <filename>/tmp/myboot</filename></userinput></screen>
|
|
|
|
<para>Having done that, if you have <devicename>vn</devicename>
|
|
configured in your kernel, you can mount the file system with:</para>
|
|
|
|
<screen>&prompt.root; <userinput>vnconfig <option>-e</option> <filename>vn0c</filename> <filename>/tmp/bootable.iso</filename></userinput>
|
|
&prompt.root; <userinput>mount <option>-t</option> cd9660 <filename>/dev/vn0c</filename> <filename>/mnt</filename></userinput></screen>
|
|
|
|
<para>At which point you can verify that <filename>/mnt</filename>
|
|
and <filename>/tmp/myboot</filename> are identical.</para>
|
|
|
|
<para>There are many other options you can use with
|
|
<command>mkisofs</command> to fine-tune its behavior. In particular:
|
|
modifications to an ISO 9660 layout and the creation of Joilet
|
|
and HFS discs. See the &man.mkisofs.8; manual page for details.</para>
|
|
</sect2>
|
|
|
|
<sect2 id="burncd">
|
|
<title>burncd</title>
|
|
<indexterm>
|
|
<primary>CDROMs</primary>
|
|
<secondary>burning</secondary>
|
|
</indexterm>
|
|
<para>If you have an ATAPI CD burner, you can use the
|
|
<command>burncd</command> command to burn an ISO image onto a
|
|
CD. <command>burncd</command> is part of the base system, installed
|
|
as <filename>/usr/sbin/burncd</filename>. Usage is very simple, as
|
|
it has few options:</para>
|
|
|
|
<screen>&prompt.root; <userinput>burncd <option>-f</option> <replaceable>cddevice</replaceable> data <replaceable>imagefile.iso</replaceable> fixate</userinput></screen>
|
|
|
|
<para>Will burn a copy of <replaceable>imagefile.iso</replaceable> on
|
|
<replaceable>cddevice</replaceable>. The default device is
|
|
<filename>/dev/acd0c</filename>. See &man.burncd.8; for options to
|
|
set the write speed, eject the CD after burning, and write audio
|
|
data.</para>
|
|
</sect2>
|
|
|
|
<sect2 id="cdrecord">
|
|
<title>cdrecord</title>
|
|
|
|
<para>If you do not have an ATAPI CD burner, you will have to use
|
|
<command>cdrecord</command> to burn your
|
|
CDs. <command>cdrecord</command> is not part of the base system;
|
|
you must install it from either the port at <port>sysutils/cdrtools</port>
|
|
or the appropriate
|
|
package. Changes to the base system can cause binary versions of
|
|
this program to fail, possibly resulting in a
|
|
<quote>coaster</quote>. You should therefore either upgrade the
|
|
port when you upgrade your system, or if you are <link
|
|
linkend="stable">tracking -STABLE</link>, upgrade the port when a
|
|
new version becomes available.</para>
|
|
|
|
<para>While <command>cdrecord</command> has many options, basic usage
|
|
is even simpler than <command>burncd</command>. Burning an ISO 9660
|
|
image is done with:</para>
|
|
|
|
<screen>&prompt.root; <userinput>cdrecord <option>dev=</option><replaceable>device</replaceable> <replaceable>imagefile.iso</replaceable></userinput></screen>
|
|
|
|
<para>The tricky part of using <command>cdrecord</command> is finding
|
|
the <option>dev</option> to use. To find the proper setting, use
|
|
the <option>-scanbus</option> flag of <command>cdrecord</command>,
|
|
which might produce results like this:</para>
|
|
<indexterm>
|
|
<primary>CDROMs</primary>
|
|
<secondary>burning</secondary>
|
|
</indexterm>
|
|
<screen>&prompt.root; <userinput>cdrecord <option>-scanbus</option></userinput>
|
|
Cdrecord 1.9 (i386-unknown-freebsd4.2) Copyright (C) 1995-2000 Jörg Schilling
|
|
Using libscg version 'schily-0.1'
|
|
scsibus0:
|
|
0,0,0 0) 'SEAGATE ' 'ST39236LW ' '0004' Disk
|
|
0,1,0 1) 'SEAGATE ' 'ST39173W ' '5958' Disk
|
|
0,2,0 2) *
|
|
0,3,0 3) 'iomega ' 'jaz 1GB ' 'J.86' Removable Disk
|
|
0,4,0 4) 'NEC ' 'CD-ROM DRIVE:466' '1.26' Removable CD-ROM
|
|
0,5,0 5) *
|
|
0,6,0 6) *
|
|
0,7,0 7) *
|
|
scsibus1:
|
|
1,0,0 100) *
|
|
1,1,0 101) *
|
|
1,2,0 102) *
|
|
1,3,0 103) *
|
|
1,4,0 104) *
|
|
1,5,0 105) 'YAMAHA ' 'CRW4260 ' '1.0q' Removable CD-ROM
|
|
1,6,0 106) 'ARTEC ' 'AM12S ' '1.06' Scanner
|
|
1,7,0 107) *</screen>
|
|
|
|
<para>This lists the appropriate <option>dev</option> value for the
|
|
devices on the list. Locate your CD burner, and use the three
|
|
numbers separated by commas as the value for
|
|
<option>dev</option>. In this case, the CRW device is 1,5,0, so the
|
|
appropriate input would be
|
|
<userinput><option>dev</option>=1,5,0</userinput>. There are easier
|
|
ways to specify this value; see &man.cdrecord.1; for
|
|
details. That is also the place to look for information on writing
|
|
audio tracks, controlling the speed, and other things.</para>
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="ccd">
|
|
<sect1info>
|
|
<authorgroup>
|
|
<author>
|
|
<firstname>Chris</firstname>
|
|
<surname>Shumway</surname>
|
|
<contrib>Written by </contrib>
|
|
</author>
|
|
</authorgroup>
|
|
<authorgroup>
|
|
<author>
|
|
<firstname>Valentino</firstname>
|
|
<surname>Vaschetto</surname>
|
|
<contrib>Marked up by </contrib>
|
|
</author>
|
|
</authorgroup>
|
|
</sect1info>
|
|
<title>ccd (Concatenated Disk Configuration)</title>
|
|
|
|
<para>It seems like today everyone has a collection of multimedia
|
|
files. Everything from mp3's to video clips. I've converted most
|
|
of my audio CDROM collection to mp3's so I can have all of my music
|
|
in one centralized location, and not have to hunt down the audio CD
|
|
with that one song I got stuck in my head. The problem I was faced
|
|
with is where to store all these files?</para>
|
|
|
|
<para>When choosing a mass storage solution, the most important
|
|
factors to consider are speed, reliability, and cost. It is very
|
|
rare to have all three in favor, normally a fast, reliable mass
|
|
storage device is expensive, and to cut back on cost either speed or
|
|
reliability must be sacrificed. In designing my system, I ranked
|
|
the requirements by most favorable to least favorable. In this
|
|
situation, cost was the biggest factor. I needed a lot of storage
|
|
for a reasonable price. The next factor, speed, is not quite as
|
|
important, since most of the usage would be over a one hundred
|
|
megabit switched Ethernet, and that would most likely be the
|
|
bottleneck. The ability to spread the file input/output operations
|
|
out over several disks would be more than enough speed for this
|
|
network. Finally, the consideration of reliability was an easy one
|
|
to answer. All of the data being put on this mass storage device
|
|
was already backed up on CD-R's. This drive was primarily here for
|
|
online live storage for easy access, so if a drive went bad, I could
|
|
just replace it, rebuild the filesystem, and copy back the data from
|
|
CD-R's.</para>
|
|
|
|
<para>To sum it up, I need something that will give
|
|
me the most amount of storage space for my money. The cost of large
|
|
IDE disks are cheap these days. I found a place that was selling
|
|
Western Digital 30.7gb 5400 RPM IDE disks for about one-hundred and
|
|
thirty US dollars. I bought three of them, giving me approximately
|
|
ninety gigabytes of online storage.</para>
|
|
|
|
<sect2 id="ccd-installhw">
|
|
<title>Installing the Hardware</title>
|
|
|
|
<para>I installed the hard drives in a system that already had
|
|
one IDE disk in as the system disk. The ideal solution would be
|
|
for each IDE disk to have its own IDE controller and cable, but
|
|
without fronting more costs to acquire a dual IDE controller
|
|
this wouldn't be a possibility. So, I jumpered two disks as
|
|
slaves, and one as master. One went on the first IDE controller
|
|
as a slave to the system disk, and the other two where
|
|
slave/master on the secondary IDE controller.</para>
|
|
|
|
<para>Upon reboot, the system BIOS was configured to
|
|
automatically detect the disks attached. More importantly,
|
|
FreeBSD 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>
|
|
|
|
<para>At this point, if FreeBSD doesn't detect the disks, be
|
|
sure that you have jumpered them correctly. I have heard
|
|
numerous reports with problems using cable select instead of
|
|
true slave/master configuration.</para>
|
|
|
|
<para>The next consideration was how to attach them as part of the
|
|
filesystem. I did a little research on
|
|
<ulink url="http://www.vinumvm.org">&man.vinum.8;</ulink> and FreeBSD's &man.ccd.4;.
|
|
In this particular configuration, &man.ccd.4; appeared to be a better
|
|
choice mainly because it has fewer parts. Less parts tends to
|
|
indicate less chance of breakage. Vinum appears to be a bit of an
|
|
overkill for my needs.</para>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="ccd-setup">
|
|
<title>Setting up the CCD</title>
|
|
|
|
<para><application>CCD</application> allows me to take several
|
|
identical disks and
|
|
concatenate them into one logical filesystem. In order to use
|
|
<application>ccd</application>, I need a kernel with
|
|
<application>ccd</application> support built into it. I added
|
|
this line to my kernel configuration file and rebuilt the
|
|
kernel:</para>
|
|
|
|
<programlisting>pseudo-device ccd 4</programlisting>
|
|
|
|
<para><application>ccd</application> support can also be loaded as a
|
|
kernel loadable module in FreeBSD 4.0 or later.</para>
|
|
|
|
<para>To set up <application>ccd</application>, first I need to
|
|
disklabel the disks. Here's how I disklabeled them:</para>
|
|
|
|
<programlisting>disklabel -r -w ad1 auto
|
|
disklabel -r -w ad2 auto
|
|
disklabel -r -w ad3 auto</programlisting>
|
|
|
|
<para>This created a disklabel ad1c, ad2c and ad3c that spans
|
|
the entire disk.</para>
|
|
|
|
<para>The next step is to change the disklabel type. To do that
|
|
I had to edit the disklabel:</para>
|
|
|
|
<programlisting>disklabel -e ad1
|
|
disklabel -e ad2
|
|
disklabel -e ad3</programlisting>
|
|
|
|
<para>This opened up the current disklabel on each disk
|
|
respectively in whatever editor the <envar>EDITOR</envar> environment variable
|
|
was set to, in my case, &man.vi.1;. Inside the editor I had a
|
|
section 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>I need to add a new "e" partition for &man.ccd.4; to use. This
|
|
can be a copy of the "c" partition. Once I was done, my
|
|
disklabel should look 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 unused 0 0 0 # (Cyl. 0 - 59597)</programlisting>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="ccd-buildingfs">
|
|
<title>Building the Filesystem</title>
|
|
|
|
<para>Now that I have all of the disks labeled, I needed to
|
|
build the <application>ccd</application>. To do that, I used a
|
|
utility called
|
|
&man.ccdconfig.8;. <command>ccdconfig</command> takes several arguments, the first
|
|
argument being the device to configure, in this case,
|
|
<devicename>/dev/ccd0c</devicename>. The device node for
|
|
<devicename>ccd0c</devicename> may not exist yet, so to create
|
|
it, preform the following commands:</para>
|
|
|
|
<programlisting>cd /dev
|
|
sh MAKEDEV ccd0</programlisting>
|
|
|
|
<para>The next argument <command>ccdconfig</command> expects is the interleave
|
|
for the filesystem. The interleave defines the size of a
|
|
stripe in disk blocks, normally five hundred and twelve bytes.
|
|
So, an interleave of thirty-two would be sixteen thousand
|
|
three hundred and eighty-four bytes.</para>
|
|
|
|
<para>After the interleave comes the flags for <command>ccdconfig</command>. If
|
|
you want to enable drive mirroring, you can specify a flag
|
|
here. In this configuration, I am not mirroring the
|
|
<application>ccd</application>, so I left it as zero.</para>
|
|
|
|
<para>The final arguments to <command>ccdconfig</command> are the devices to place
|
|
into the array. Putting it all together I get this
|
|
command:</para>
|
|
|
|
<programlisting>ccdconfig ccd0 32 0 /dev/ad1c /dev/ad2c /dev/ad3c</programlisting>
|
|
|
|
<para>This configures the <application>ccd</application>.
|
|
I can now &man.newfs.8; the filesystem.</para>
|
|
|
|
<programlisting>newfs /dev/ccd0c</programlisting>
|
|
|
|
</sect2>
|
|
<sect2 id="ccd-auto">
|
|
<title>Making It All Automagic</title>
|
|
|
|
<para>Finally, if I want to be able to mount the
|
|
<application>ccd</application>, I need to
|
|
configure it first. I write out my current configuration to
|
|
<filename>/etc/ccd.conf</filename> using the following command:</para>
|
|
|
|
<programlisting>ccdconfig -g > /etc/ccd.conf</programlisting>
|
|
|
|
<para>When I reboot, the script <command>/etc/rc</command> runs
|
|
<command>ccdconfig -C</command> if /etc/ccd.conf exists. This
|
|
automatically configures the <application>ccd</application>
|
|
so it can be mounted.</para>
|
|
|
|
<para>If you are booting into single user mode, before you can
|
|
<command>mount</command> the <application>ccd</application>, you
|
|
need to issue the following command to configure the
|
|
array:</para>
|
|
|
|
<programlisting>ccdconfig -C</programlisting>
|
|
|
|
<para>Then, we need an entry for the <application>ccd</application>
|
|
in <filename>/etc/fstab</filename> so it
|
|
will be mounted at boot time.</para>
|
|
|
|
<programlisting>/dev/ccd0c /media ufs rw 2 2</programlisting>
|
|
</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:
|
|
-->
|