Date: Tue, 26 Feb 2002 13:10:02 -0800 (PST) From: Tom Rhodes <darklogik@pittgoth.com> To: freebsd-doc@freebsd.org Subject: Re: docs/35098: [PATCH] Handbook NFS stuff Message-ID: <200202262110.g1QLA2f07435@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
The following reply was made to PR docs/35098; it has been noted by GNATS.
From: Tom Rhodes <darklogik@pittgoth.com>
To: FreeBSD-gnats-submit@FreeBSD.org
Cc:
Subject: Re: docs/35098: [PATCH] Handbook NFS stuff
Date: Tue, 26 Feb 2002 16:10:17 -0500 (EST)
Try this one now ;) Clean up of whitespace, and other little "picks"
--
Tom Rhodes
diff -ru handbook.old/advanced-networking/chapter.sgml handbook/advanced-networking/chapter.sgml
--- handbook.old/advanced-networking/chapter.sgml Fri Feb 22 16:16:17 2002
+++ handbook/advanced-networking/chapter.sgml Tue Feb 26 15:45:36 2002
@@ -648,6 +648,13 @@
<sect1info>
<authorgroup>
<author>
+ <firstname>Tom</firstname>
+ <surname>Rhodes</surname>
+ <contrib>Reorganized and enhanced by </contrib>
+ </author>
+ </authorgroup>
+ <authorgroup>
+ <author>
<firstname>Bill</firstname>
<surname>Swingle</surname>
<contrib>Written by </contrib>
@@ -658,44 +665,41 @@
<indexterm><primary>NFS</primary></indexterm>
<para>Among the many different file systems that FreeBSD supports is
- the Network File System or NFS. NFS allows you
- to share directories and files on one machine with others
- via the network they are attached to. Using NFS, users and
- programs can access files on remote systems as if they were local
+ the Network File System, also known as <acronym>NFS</acronym>.
+ <acronym>NFS</acronym> allows a system to share directories and files
+ with others over a network. By using <acronym>NFS</acronym>, users and
+ programs can access files on remote systems almost as if they were local
files.</para>
- <para>NFS has several benefits:</para>
+ <para>Some of the most notable benefits that <acronym>NFS</acronym> can provide are:</para>
<itemizedlist>
<listitem>
- <para>Local workstations do not need as much disk space because
+ <para>Local workstations use less disk space because
commonly used data can be stored on a single machine and still
- remain accessible to everyone on the network.</para>
+ remain accessible to others over the network.</para>
</listitem>
<listitem>
<para>There is no need for users to have unique home directories
- on every machine on your network. Once they have an established
- directory that is available via NFS it can be accessed from
- anywhere.</para>
+ on every network machine. Home directories could be setup on the
+ <acronym>NFS</acronym> server and made available throughout the network.</para>
</listitem>
<listitem>
- <para>Storage devices such as floppies and CDROM drives can be
- used by other machines on the network eliminating the need for
- extra hardware.</para>
+ <para>Storage devices such as floppy disks, CDROM drives, and ZIP drives
+ can be used by other machines on the network. This may reduce the number
+ of removable media drives.</para>
</listitem>
</itemizedlist>
<sect2>
- <title>How It Works</title>
+ <title>How <acronym>NFS</acronym> Works</title>
- <para>NFS is composed of two sides – a client side and a
- server side. Think of it as a want/have relationship. The client
- <emphasis>wants</emphasis> the data that the server side
- <emphasis>has</emphasis>. The server shares its data with the
- client. In order for this system to function properly a few
- processes have to be configured and running.</para>
+ <para><acronym>NFS</acronym> consists of at least two main parts: a server
+ and at least one client. The client remotely accesses the data that is stored
+ on the server machine. In order for this to function properly a few
+ processes have to be configured and running:</para>
<para>The server has to be running the following daemons:</para>
<indexterm>
@@ -723,141 +727,129 @@
<tbody>
<row>
<entry>nfsd</entry>
- <entry>The NFS Daemon which services requests from NFS
- clients.</entry>
+ <entry>The <acronym>NFS</acronym> daemon which services requests from
+ the <acronym>NFS</acronym> clients.</entry>
</row>
<row>
<entry>mountd</entry>
- <entry>The NFS Mount Daemon which actually carries out
- requests that &man.nfsd.8; passes on to it.</entry>
+ <entry>The <acronym>NFS</acronym> mount daemon which carries out
+ the requests that &man.nfsd.8; passes on to it.</entry>
</row>
<row>
<entry>portmap</entry>
- <entry> The <command>portmapper</command> daemon which
- allows NFS clients to find out which port the NFS server
- is using.</entry>
+ <entry> The portmapper daemon
+ allows <acronym>NFS</acronym> clients to discover which port the <acronym>NFS</acronym> server
+ is using.</entry>
</row>
</tbody>
</tgroup>
</informaltable>
- <para>The client side only needs to run a single daemon:</para>
- <indexterm>
- <primary>NFS</primary>
- <secondary>client</secondary>
- </indexterm>
- <indexterm>
- <primary><application>nfsiod</application></primary>
- </indexterm>
-
- <informaltable frame="none">
- <tgroup cols="2">
- <tbody>
- <row>
- <entry>nfsiod</entry>
- <entry>The NFS async I/O Daemon which services requests
- from its NFS server.</entry>
- </row>
- </tbody>
- </tgroup>
- </informaltable>
+ <para>The client can also run a daemon, known as
+ <application>nfsiod</application>. The <application>nfsiod</application>
+ daemon services the requests from the <acronym>NFS</acronym> server. This
+ is optional, and improves performance, but is not required for normal
+ and correct operation. See the &man.nfsiod.8; man page for more information.
+ </para>
</sect2>
<sect2 id="configuring-nfs">
- <title>Configuring NFS</title>
+ <title>Configuring <acronym>NFS</acronym></title>
<indexterm>
<primary>NFS</primary>
<secondary>configuration</secondary>
</indexterm>
- <para>Luckily for us, on a FreeBSD system this setup is a snap. The
- processes that need to be running can all be run at boot time with
+ <para><acronym>NFS</acronym> configuration is relatively straightforward
+ process. The processes that need to be running can all start at boot time with
a few modifications to your <filename>/etc/rc.conf</filename>
- file.</para>
+ file.</para>
- <para>On the NFS server make sure you have:</para>
+ <para>On the <acronym>NFS</acronym> server, make sure that the following options
+ are configured in the <filename>/etc/rc.conf</filename> file:</para>
<programlisting>portmap_enable="YES"
nfs_server_enable="YES"
-nfs_server_flags="-u -t -n 4"
mountd_flags="-r"</programlisting>
- <para><command>mountd</command> is automatically run whenever the
- NFS server is enabled. The <option>-u</option> and
- <option>-t</option> flags to <command>nfsd</command> tell it to
- serve UDP and TCP clients. The <option>-n 4</option> flag tells
- <command>nfsd</command> to start 4 copies of itself.</para>
+ <para><command>mountd</command> runs automatically whenever the
+ <acronym>NFS</acronym> server is enabled.
- <para>On the client, make sure you have:</para>
+ <para>On the client, make sure this option is present in
+ <filename>/etc/rc.conf</filename>:</para>
<programlisting>nfs_client_enable="YES"
-nfs_client_flags="-n 4"</programlisting>
-
- <para>Like <command>nfsd</command>, the <option>-n 4</option> tells
- <command>nfsiod</command> to start 4 copies of itself.</para>
+ </programlisting>
- <para>The last configuration step requires that you create a file
- called <filename>/etc/exports</filename>. The exports file
- specifies which file systems on your server will be shared
- (a.k.a., <quote>exported</quote>) and with what clients they will
- be shared. Each line in the file specifies a file system to be
- shared. There are a handful of options that can be used in this
- file but only a few will be mentioned here. You can find out
- about the rest in the &man.exports.5; manual page.</para>
+ <para>
+ The <filename>/etc/exports</filename>
+ file specifies which filesystems <acronym>NFS</acronym> should export (sometimes
+ referred to as <quote>share</quote>).
+ Each line in <filename>/etc/exports</filename> specifies a filesystem to be exported and
+ which machines have access to that filesystem. Along with what machines have access
+ to that filesystem, access options may also be specified. There are many such options
+ that can be used in this file but only a few will be mentioned here. You can easily discover
+ other options by reading over the &man.exports.5; manual page.
+ </para>
<para>Here are a few example <filename>/etc/exports</filename>
entries:</para>
<indexterm>
<primary>NFS</primary>
- <secondary>exporting filesystems</secondary>
+ <secondary>Examples of exporting filesystems</secondary>
</indexterm>
- <para>The following line exports <filename>/cdrom</filename> to
- three silly machines that have the same domain name as the server
+
+ <para>The following examples give an idea of how to export filesystems,
+ although the settings may be different depending on
+ your environment and network configuration.
+ The following line exports <filename>/cdrom</filename> to
+ three example machines that have the same domain name as the server
(hence the lack of a domain name for each) or have entries in your
<filename>/etc/hosts</filename> file. The <option>-ro</option>
- flag makes the shared file system read-only. With this flag, the
- remote system will not be able to make any changes to the
- shared file system.</para>
+ flag makes the exported file system read-only. With this flag, the
+ remote system will not be able to write any changes to the
+ exported file system.</para>
- <programlisting>/cdrom -ro moe larry curly</programlisting>
+ <programlisting>/cdrom -ro host1 host2 host3</programlisting>
<para>The following line exports <filename>/home</filename> to three
hosts by IP address. This is a useful setup if you have a
- private network but do not have DNS running. The
- <option>-alldirs</option> flag allows all the directories below
- the specified file system to be exported as well.</para>
+ private network without a <acronym>DNS</acronym> server configured.
+ Optionally the <filename>/etc/hosts</filename> file could be configured
+ for internal hostnames; please review &man.hosts.5; for more
+ information. The <option>-alldirs</option> flag allows the directories
+ below the specified filesystem to also be exported.</para>
<programlisting>/home -alldirs 10.0.0.2 10.0.0.3 10.0.0.4</programlisting>
- <para>The following line exports <filename>/a</filename> to two
- machines that have different domain names than the server. The
- <option>-maproot=0</option> flag allows
- the root user on the remote system to write to the shared
- file system as root. Without the -maproot=0 flag even if
- someone has root access on the remote system they will not
- be able to modify files on the shared file system.</para>
+ <para>The following line exports <filename>/a</filename> so that two
+ clients from different domains may access the filesystem. The
+ <option>-maproot=0</option> flag allows the <username>root</username>
+ user on the remote system to write data on the exported filesystem as
+ <username>root</username>. If the -maproot=0 flag is not specified, then even if
+ a user has <username>root</username> access on the remote system, they will not
+ be able to modify files on the exported filesystem.</para>
- <programlisting>/a -maproot=0 host.domain.com box.example.com</programlisting>
+ <programlisting>/a -maproot=0 host.example.com box.example.org</programlisting>
- <para>In order for a client to access- an exported file system it must
- have permission to do so. Make sure your client is listed in your
+ <para>In order for a client to access an exported filesystem, the client must
+ have permission to do so. Make sure the client is listed in your
<filename>/etc/exports</filename> file.</para>
<para>In <filename>/etc/exports</filename>, each line represents
the export information for one filesystem to one host. A
- remote host can only be specified once for each local
- filesystem, and you can only have one default entry per local
- filesystem. For example, let's assume that
- <filename>/usr</filename> is a single filesystem. The
- following <filename>/etc/exports</filename> is invalid:</para>
+ remote host can only be specified once per filesystem, and may only
+ have one default entry. For example, assume that <filename>/usr</filename>
+ is a single filesystem. The following <filename>/etc/exports</filename>
+ would be valid:</para>
<programlisting>/usr/src client
/usr/ports client</programlisting>
<para>One filesystem, <filename>/usr</filename>, has two lines
- specifying its exports to the same host,
- <hostid>client</hostid>. The correct format is:</para>
+ specifying exports to the same host, <hostid>client</hostid>.
+ The correct format for this situation is:</para>
<programlisting>/usr/src /usr/ports client</programlisting>
@@ -874,40 +866,41 @@
# client01 has root privileges on it
/usr/src /usr/ports -maproot=0 client01
/usr/src /usr/ports client02
-# The "client" machines have root and can mount anywhere
-# up /exports. Anyone inhe world can mount /exports/obj read-only
+# The client machines have root and can mount anywhere
+# on /exports. Anyone in the world can mount /exports/obj read-only
/exports -alldirs -maproot=0 client01 client02
/exports/obj -ro</programlisting>
<para>You must restart
<command>mountd</command> whenever you modify
- <filename>/etc/exports</filename> to make changes take
- effect. This can be accomplished by sending the hangup signal
+ <filename>/etc/exports</filename> so the changes can take effect.
+ This can be accomplished by sending the hangup signal
to the <command>mountd</command> process:</para>
<screen>&prompt.root; <userinput>kill -HUP `cat /var/run/mountd.pid`</userinput></screen>
- <para>Now that you have made all these changes you can just reboot
- and let FreeBSD start everything for you at boot time, or you can
- run the following commands as root:</para>
+ <para>Alternatively, a reboot will make FreeBSD set everything
+ up properly. A reboot is not necessary though.
+ Executing the following commands as <username>root</username>,
+ should start everything up.</para>
- <para>On the NFS server:</para>
+ <para>On the <acronym>NFS</acronym> server:</para>
<screen>&prompt.root; <userinput>portmap</userinput>
&prompt.root; <userinput>nfsd -u -t -n 4</userinput>
&prompt.root; <userinput>mountd -r</userinput></screen>
- <para>On the NFS client:</para>
+ <para>On the <acronym>NFS</acronym> client:</para>
<screen>&prompt.root; <userinput>nfsiod -n 4</userinput></screen>
- <para>Now you should be ready to actually mount a remote file
- system. This can be done one of two ways. In these examples the
+ <para>Now everything should be ready to actually mount a remote file
+ system. In these examples the
server's name will be <literal>server</literal> and the client's
- name will be <literal>client</literal>. If you just want to
- temporarily mount a remote file system or just want to test out
- your configuration you can run a command like this as root on the
- client:</para>
+ name will be <literal>client</literal>. If you only want to
+ temporarily mount a remote file system or would rather test the
+ configuration, just execute a command like this as <username>root</username> on the
+ client:</para>
<indexterm>
<primary>NFS</primary>
<secondary>mounting filesystems</secondary>
@@ -916,56 +909,59 @@
<para>This will mount the <filename>/home</filename> directory
on the server at <filename>/mnt</filename> on the client. If
- everything is setup correctly you should be able to go into
- /mnt on the client and see all the files that are on the
- server.</para>
-
- <para>If you want to automatically mount a remote file system
- each time the computer boots, add the filesystem to
- <filename>/etc/fstab</filename>. Here is an example:</para>
+ everything is set up correctly you should be able to enter
+ <filename>/mnt</filename> on the client and see all the files
+ that are on the server.</para>
+
+ <para>If you want to automatically mount a remote filesystem
+ each time the computer boots, add the filesystem to the
+ <filename>/etc/fstab</filename> file. Here is an example:</para>
<programlisting>server:/home /mnt nfs rw 0 0</programlisting>
- <para>Read the &man.fstab.5; manual page for more options.</para>
+ <para>The &man.fstab.5; manual page lists all the available options.</para>
</sect2>
<sect2>
<title>Practical Uses</title>
- <para>There are many very cool uses for NFS. Some of the more common
- ones are listed below.</para>
+ <para><acronym>NFS</acronym> has many practical uses. Some of the more common
+ ones are listed below:</para>
+
+ <note><para>The following <acronym>NFS</acronym> examples require
+ <acronym>NFS</acronym> to be correctly configured before actual use,
+ as previously discussed.</para>
+ </note>
+
<indexterm>
<primary>NFS</primary>
<secondary>uses</secondary>
</indexterm>
<itemizedlist>
<listitem>
- <para>Have several machines on a network and share a CDROM or
- floppy drive among them. This is cheaper and often more
- convenient.</para>
+ <para>Set several machines to share a CDROM or
+ other media among them. This is cheaper and often
+ more convenient.</para>
</listitem>
<listitem>
- <para>With so many machines on a network, it gets old having your
- personal files strewn all over the place. You can have a
- central NFS server that houses all user home directories and
- shares them with the rest of the machines on the LAN, so no
- matter where you log in you will have the same home
- directory.</para>
+ <para>On large networks, it might be more convenient to configure a
+ central <acronym>NFS</acronym> server in which to store all the user
+ home directories. These home directories can then be exported to
+ the network so that users would always have the same home directory,
+ regardless of which workstation they log in to.</para>
</listitem>
<listitem>
- <para>When you get to reinstalling FreeBSD on one of your
- machines, NFS is the way to go! Just pop your distribution
- CDROM into your file server and away you go!</para>
+ <para>You can use an exported CDROM to install
+ software on multiple machines.</para>
</listitem>
<listitem>
- <para>Have a common <filename>/usr/ports/distfiles</filename>
- directory that all your machines share. That way, when you go
- to install a port that you have already installed on a different
- machine, you do not have to download the source all over
- again!</para>
+ <para>Several machines could have a common <filename>/usr/ports/distfiles</filename>
+ directory.
+ That way, when you need to install a port on several machines, you can
+ quickly access the source without downloading it on each machine.</para>
</listitem>
</itemizedlist>
</sect2>
@@ -992,14 +988,15 @@
<indexterm><primary>amd</primary></indexterm>
<indexterm><primary>automatic mounter daemon</primary></indexterm>
- <para>&man.amd.8;, which is also known as the automatic mounter
- daemon, is a useful utility used for automatically mounting a
+ <para>&man.amd.8; (the automatic mounter daemon)
+ is a useful that automatically mounts a
remote filesystem whenever a file or directory within that
filesystem is accessed. Filesystems that are inactive for a
period of time will also be automatically unmounted by
<application>amd</application>. Using
- <application>amd</application> provides a simplistic alternative
- to static mounts.</para>
+ <application>amd</application> provides a simple alternative
+ to permanent mounts, as permanent mounts should be listed in the
+ <filename>/etc/fstab</filename>.</para>
<para><application>amd</application> operates by attaching
itself as an NFS server to the <filename>/host</filename> and
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-doc" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200202262110.g1QLA2f07435>