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Editorial review of NFS chapter.

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Divide config section into server stuff and client stuff.

Sponsored by:	iXsystems
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Dru Lavigne 2014-04-03 19:05:05 +00:00
parent 5fbf39a916
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Notes: svn2git 2020-12-08 03:00:23 +00:00 
svn path=/head/; revision=44430
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@ -472,25 +472,28 @@ server-program-arguments</programlisting>
</sect1> </sect1>
<sect1 xml:id="network-nfs"> <sect1 xml:id="network-nfs">
<!-- <info>
<sect1info> <title>Network File System (NFS)</title>
<authorgroup> <authorgroup>
<author> <author>
<personname>
<firstname>Tom</firstname> <firstname>Tom</firstname>
<surname>Rhodes</surname> <surname>Rhodes</surname>
</personname>
<contrib>Reorganized and enhanced by </contrib> <contrib>Reorganized and enhanced by </contrib>
</author> </author>
</authorgroup> </authorgroup>
<authorgroup> <authorgroup>
<author> <author>
<personname>
<firstname>Bill</firstname> <firstname>Bill</firstname>
<surname>Swingle</surname> <surname>Swingle</surname>
</personname>
<contrib>Written by </contrib> <contrib>Written by </contrib>
</author> </author>
</authorgroup> </authorgroup>
</sect1info> </info>
-->
<title>Network File System (NFS)</title>
<indexterm><primary>NFS</primary></indexterm> <indexterm><primary>NFS</primary></indexterm>
<para>&os; supports the Network File System <para>&os; supports the Network File System
@ -499,8 +502,8 @@ server-program-arguments</programlisting>
<acronym>NFS</acronym>, users and programs can access files on <acronym>NFS</acronym>, users and programs can access files on
remote systems as if they were stored locally.</para> remote systems as if they were stored locally.</para>
<para>The most notable benefits that <para><acronym>NFS</acronym> has many practical uses. Some of
<acronym>NFS</acronym> provides are:</para> the more common uses include:</para>
<itemizedlist> <itemizedlist>
<listitem> <listitem>
@ -510,13 +513,24 @@ server-program-arguments</programlisting>
</listitem> </listitem>
<listitem> <listitem>
<para>User home directories can be stored in one location <para>Several clients may need access to the
and accessed by their owners over the network.</para> <filename>/usr/ports/distfiles</filename> directory.
Sharing that directory allows for quick access to the
source files without having to download them to each
client.</para>
</listitem>
<listitem>
<para>On large networks, it is often more convenient to
configure a central <acronym>NFS</acronym> server on which
all user home directories are stored. Users can log into
a client anywhere on the network and have access to their
home directories.</para>
</listitem> </listitem>
<listitem> <listitem>
<para>Administration of <acronym>NFS</acronym> exports is <para>Administration of <acronym>NFS</acronym> exports is
also simplified. For example, there is only one file simplified. For example, there is only one file
system where security or backup policies must be system where security or backup policies must be
set.</para> set.</para>
</listitem> </listitem>
@ -525,14 +539,16 @@ server-program-arguments</programlisting>
<para>Removable media storage devices can be used by other <para>Removable media storage devices can be used by other
machines on the network. This reduces the number of devices machines on the network. This reduces the number of devices
throughout the network and provides a centralized location throughout the network and provides a centralized location
to manage their security.</para> to manage their security. It is often more convenient to
install software on multiple machines from a centralized
installation media.</para>
</listitem> </listitem>
</itemizedlist> </itemizedlist>
<para><acronym>NFS</acronym> consists of at least two main <para><acronym>NFS</acronym> consists of
parts: a server and one or more clients. The client a server and one or more clients. The client
remotely accesses the data that is stored on the server remotely accesses the data that is stored on the server
machine. In order for this to function properly a few machine. In order for this to function properly, a few
processes have to be configured and running.</para> processes have to be configured and running.</para>
<para>These daemons must be running on the server:</para> <para>These daemons must be running on the server:</para>
@ -571,15 +587,14 @@ server-program-arguments</programlisting>
<row> <row>
<entry><application>nfsd</application></entry> <entry><application>nfsd</application></entry>
<entry>The <acronym>NFS</acronym> daemon which services <entry>The <acronym>NFS</acronym> daemon which services
requests from the <acronym>NFS</acronym> requests from <acronym>NFS</acronym>
clients.</entry> clients.</entry>
</row> </row>
<row> <row>
<entry><application>mountd</application></entry> <entry><application>mountd</application></entry>
<entry>The <acronym>NFS</acronym> mount daemon which <entry>The <acronym>NFS</acronym> mount daemon which
carries out the requests that &man.nfsd.8; passes on carries out requests received from <application>nfsd</application>.</entry>
to it.</entry>
</row> </row>
<row> <row>
@ -592,120 +607,98 @@ server-program-arguments</programlisting>
</tgroup> </tgroup>
</informaltable> </informaltable>
<para>Running &man.nfsiod.8; can improve performance on the <para>Running &man.nfsiod.8; on the
client, but is not required.</para> client can improve performance, but is not required.</para>
<sect2 xml:id="network-configuring-nfs"> <sect2 xml:id="network-configuring-nfs">
<title>Configuring <acronym>NFS</acronym></title> <title>Configuring the Server</title>
<indexterm> <indexterm>
<primary>NFS</primary> <primary>NFS</primary>
<secondary>configuration</secondary> <secondary>configuration</secondary>
</indexterm> </indexterm>
<para>Enabling the <acronym>NFS</acronym> server <para>The file systems which the <acronym>NFS</acronym> server will
is straightforward. The required processes share are specified in <filename>/etc/exports</filename>. Each
can be set to start at boot time by adding line in this file specifies a file
these options to system to be exported, which clients have access to that
<filename>/etc/rc.conf</filename>:</para> file system, and any access options. When adding entries to this file,
each exported file system, its properties, and allowed
<programlisting>rpcbind_enable="YES" hosts must occur on a single line. If no clients are listed in the entry,
nfs_server_enable="YES" then any client on the network can mount that file
mountd_flags="-r"</programlisting> system.</para>
<para><application>mountd</application> runs automatically
whenever the <acronym>NFS</acronym> server is enabled.</para>
<para>To enable the client, set this option in
<filename>/etc/rc.conf</filename>:</para>
<programlisting>nfs_client_enable="YES"</programlisting>
<para><filename>/etc/exports</filename> specifies which file
systems the <acronym>NFS</acronym> server will export. Each
line in <filename>/etc/exports</filename> specifies a file
system to be exported and which clients have access to that
file system, as well as any access options. There are many
such options that can be used in this file, but only a few
will be mentioned here. See &man.exports.5; for the full list
of options.</para>
<indexterm> <indexterm>
<primary>NFS</primary> <primary>NFS</primary>
<secondary>export examples</secondary> <secondary>export examples</secondary>
</indexterm> </indexterm>
<para>These examples give an idea of how to export file systems. <para>The following <filename>/etc/exports</filename> entries
Minor modifications may be required for the examples to work demonstrate how to export file systems.
on the reader's network.</para> The examples can be modified to match the file systems
and client names on the reader's network. There are many
options that can be used in this file, but only a few
will be mentioned here. See &man.exports.5; for the full list
of options.</para>
<para>This example shows how to export the <para>This example shows how to export
<filename>/cdrom</filename> directory to <filename>/cdrom</filename> to
three clients called <replaceable>alpha</replaceable>, three hosts named <replaceable>alpha</replaceable>,
<replaceable>bravo</replaceable>, and <replaceable>bravo</replaceable>, and
<replaceable>charlie</replaceable>:</para> <replaceable>charlie</replaceable>:</para>
<programlisting>/cdrom -ro <replaceable>alpha</replaceable> <replaceable>bravo</replaceable> <replaceable>charlie</replaceable></programlisting> <programlisting>/cdrom -ro <replaceable>alpha</replaceable> <replaceable>bravo</replaceable> <replaceable>charlie</replaceable></programlisting>
<para>The <literal>-ro</literal> flag makes the file systems <para>The <literal>-ro</literal> flag makes the file system
read-only, preventing clients from making any changes to read-only, preventing clients from making any changes to
those exported file systems.</para> the exported file system. This example assumes that the host
names are either in <acronym>DNS</acronym> or in
<filename>/etc/hosts</filename>. Refer to &man.hosts.5; if
the network does not have a <acronym>DNS</acronym>
server.</para>
<para>The next example exports <filename>/home</filename> to <para>The next example exports <filename>/home</filename> to
three clients by <acronym>IP</acronym> address. This can be three clients by <acronym>IP</acronym> address. This can be
useful for networks without <acronym>DNS</acronym>. useful for networks without <acronym>DNS</acronym> or
Optionally, <filename>/etc/hosts</filename> could be <filename>/etc/hosts</filename> entries.
configured for internal hostnames; please review &man.hosts.5; The <literal>-alldirs</literal> flag
for more information. The <literal>-alldirs</literal> flag
allows subdirectories to be mount points. In other words, it allows subdirectories to be mount points. In other words, it
will not mount the subdirectories but permit the client to will not automaticaly mount the subdirectories, but will permit the client to
mount only the directories that are required or needed.</para> mount the directories that are required as needed.</para>
<programlisting>/home -alldirs 10.0.0.2 10.0.0.3 10.0.0.4</programlisting> <programlisting>/home -alldirs 10.0.0.2 10.0.0.3 10.0.0.4</programlisting>
<para>This next line exports <filename>/a</filename> so that two <para>This next example exports <filename>/a</filename> so that two
clients from different domains may access the file system. clients from different domains may access that file system.
The <option>-maproot=root</option> flag allows the The <option>-maproot=root</option> allows
<systemitem class="username">root</systemitem> user on the <systemitem class="username">root</systemitem> on the
remote system to write data on the exported file system as remote system to write data on the exported file system as
<systemitem class="username">root</systemitem>. If the <systemitem class="username">root</systemitem>. If
<literal>-maproot=root</literal> flag is not specified, the <literal>-maproot=root</literal> is not specified, the
client's <systemitem class="username">root</systemitem> user client's <systemitem class="username">root</systemitem> user
will be mapped to the server's <systemitem will be mapped to the server's <systemitem
class="username">nobody</systemitem> account and will be class="username">nobody</systemitem> account and will be
subject to the access limitations defined for user, subject to the access limitations defined for
<systemitem class="username">nobody</systemitem>.</para> <systemitem class="username">nobody</systemitem>.</para>
<programlisting>/a -maproot=root host.example.com box.example.org</programlisting> <programlisting>/a -maproot=root host.example.com box.example.org</programlisting>
<para>For a client to have access to an exported file system, <para>A client can only be specified once per file
the client must be listed in system. For example, if
<filename>/etc/exports</filename>.</para> <filename>/usr</filename> is a single file system, these
entries would be
<para>In <filename>/etc/exports</filename>, each line defines invalid as both entries
the export information for one file system to one or more specify the same host:</para>
clients. A remote host can only be specified once per file
system. For example, assume that
<filename>/usr</filename> is a single file system. This
entry, in <filename>/etc/exports</filename>, would be
invalid:</para>
<programlisting># Invalid when /usr is one file system <programlisting># Invalid when /usr is one file system
/usr/src client /usr/src client
/usr/ports client</programlisting> /usr/ports client</programlisting>
<para>The <filename>/usr</filename> file system has two lines <para>The correct format for this
specifying exports to the same host, situation is to use one entry:</para>
<systemitem>client</systemitem>. The correct format for this
situation is:</para>
<programlisting>/usr/src /usr/ports client</programlisting> <programlisting>/usr/src /usr/ports client</programlisting>
<para>The exported file system, its properties, and allowed
hosts must occur on a single line. If no clients are listed,
then any client on the network may mount the exported file
system.</para>
<para>The following is an example of a valid export list, where <para>The following is an example of a valid export list, where
<filename>/usr</filename> and <filename>/exports</filename> <filename>/usr</filename> and <filename>/exports</filename>
are local file systems:</para> are local file systems:</para>
@ -719,35 +712,50 @@ mountd_flags="-r"</programlisting>
/exports -alldirs -maproot=root client01 client02 /exports -alldirs -maproot=root client01 client02
/exports/obj -ro</programlisting> /exports/obj -ro</programlisting>
<para>The <application>mountd</application> daemon reads <para>To enable the processes required by the <acronym>NFS</acronym> server
<filename>/etc/exports</filename> when started. To make at boot time, add
<acronym>NFS</acronym> server changes take effect immediately, these options to
force <application>mountd</application> to reread <filename>/etc/rc.conf</filename>:</para>
<filename>/etc/exports</filename>:</para>
<screen>&prompt.root; <userinput>service mountd reload</userinput></screen> <programlisting>rpcbind_enable="YES"
nfs_server_enable="YES"
mountd_flags="-r"</programlisting>
<para>Please refer to <xref linkend="configtuning-rcd"/> for <para>The server can be started now by
more information about using rc scripts.</para> running this command:</para>
<para>On a new server being configured with
<acronym>NFS</acronym> services, the server can be started by
running this command as <systemitem
class="username">root</systemitem>:</para>
<screen>&prompt.root; <userinput>service nfsd start</userinput></screen> <screen>&prompt.root; <userinput>service nfsd start</userinput></screen>
<para>On the <acronym>NFS</acronym> client:</para> <para>Whenever the <acronym>NFS</acronym> server is started,
<application>mountd</application> also starts automatically.
However, <application>mountd</application> only reads
<filename>/etc/exports</filename> when it is started. To make subsequent
<filename>/etc/exports</filename> edits take effect immediately,
force <application>mountd</application> to reread it:</para>
<screen>&prompt.root; <userinput>service nfsclient restart</userinput></screen> <screen>&prompt.root; <userinput>service mountd reload</userinput></screen>
</sect2>
<sect2>
<title>Configuring the Client</title>
<para>To enable <acronym>NFS</acronym> clients, set this option in each client's
<filename>/etc/rc.conf</filename>:</para>
<programlisting>nfs_client_enable="YES"</programlisting>
<para>Then, run this command on each <acronym>NFS</acronym>
client:</para>
<screen>&prompt.root; <userinput>service nfsclient start</userinput></screen>
<para>The client now has everything it needs to mount a remote <para>The client now has everything it needs to mount a remote
file system. In these examples, the server's name is file system. In these examples, the server's name is
<systemitem>server</systemitem> and the client's name is <systemitem>server</systemitem> and the client's name is
<systemitem>client</systemitem>. For testing or to <systemitem>client</systemitem>. To
temporarily mount a remote file system, execute mount the <filename>/home</filename> file system on
<application>mount</application> as <systemitem <systemitem>server</systemitem> to the
class="username">root</systemitem> on <filename>/mnt</filename> mount point on
<systemitem>client</systemitem>:</para> <systemitem>client</systemitem>:</para>
<indexterm> <indexterm>
@ -756,12 +764,9 @@ mountd_flags="-r"</programlisting>
</indexterm> </indexterm>
<screen>&prompt.root; <userinput>mount server:/home /mnt</userinput></screen> <screen>&prompt.root; <userinput>mount server:/home /mnt</userinput></screen>
<para>This mounts the <systemitem>server</systemitem>: <para>The files and
<filename>/home</filename> file system to the directories in
<systemitem>client</systemitem>: <filename>/home</filename> will now be available
<filename>/mnt</filename> mount point. The files and
directories in the <systemitem>server</systemitem>
<filename>/home</filename> file system will now be available
on <systemitem>client</systemitem>, in the on <systemitem>client</systemitem>, in the
<filename>/mnt</filename> directory.</para> <filename>/mnt</filename> directory.</para>
@ -777,117 +782,75 @@ mountd_flags="-r"</programlisting>
<sect2> <sect2>
<title>Locking</title> <title>Locking</title>
<para>Some applications (e.g., <application>mutt</application>) <para>Some applications
require file locking to operate correctly. In the case of require file locking to operate correctly. To enable locking, add these lines to
<acronym>NFS</acronym>, <application>rpc.lockd</application> <filename>/etc/rc.conf</filename> on both the client and
can be used for file locking. To enable it, add this line to
<filename>/etc/rc.conf</filename> on both client and
server:</para> server:</para>
<programlisting>rpc_lockd_enable="YES" <programlisting>rpc_lockd_enable="YES"
rpc_statd_enable="YES"</programlisting> rpc_statd_enable="YES"</programlisting>
<para>Please note that this assumes that both <para>Then start the applications:</para>
<acronym>NFS</acronym> client and server are already
configured.</para>
<para>Start the application, as <systemitem
class="username">root</systemitem>, with:</para>
<screen>&prompt.root; <userinput>service lockd start</userinput> <screen>&prompt.root; <userinput>service lockd start</userinput>
&prompt.root; <userinput>service statd start</userinput></screen> &prompt.root; <userinput>service statd start</userinput></screen>
<para>If locking is not required on the server, the <para>If locking is not required on the server, the
<acronym>NFS</acronym> client can be configured to lock <acronym>NFS</acronym> client can be configured to lock
locally by passing <option>-L</option> to &man.mount.nfs.8;. locally by including <option>-L</option> when running <application>mount</application>.
Refer to &man.mount.nfs.8; for further details.</para> Refer to &man.mount.nfs.8; for further details.</para>
</sect2> </sect2>
<sect2>
<title>Practical Uses</title>
<para><acronym>NFS</acronym> has many practical uses. Some of
the more common uses:</para>
<indexterm>
<primary>NFS</primary>
<secondary>uses</secondary>
</indexterm>
<itemizedlist>
<listitem>
<para>Share a <acronym>CD-ROM</acronym> or other media with
any number of clients. It is often more convenient to
install software on multiple machines from a single
location.</para>
</listitem>
<listitem>
<para>On large networks, it is often more convenient to
configure a central <acronym>NFS</acronym> server on which
all user home directories are stored. Users can log into
a client anywhere on the network and have access to their
home directories.</para>
</listitem>
<listitem>
<para>Several clients may need access to the
<filename>/usr/ports/distfiles</filename> directory.
Sharing that directory allows for quick access to the
source files without having to download them to each
client.</para>
</listitem>
</itemizedlist>
</sect2>
<sect2 xml:id="network-amd"> <sect2 xml:id="network-amd">
<!-- <info>
<sect2info> <title>Automating Mounts</title>
<authorgroup> <authorgroup>
<author> <author>
<personname>
<firstname>Wylie</firstname> <firstname>Wylie</firstname>
<surname>Stilwell</surname> <surname>Stilwell</surname>
</personname>
<contrib>Contributed by </contrib> <contrib>Contributed by </contrib>
</author> </author>
</authorgroup> </authorgroup>
<authorgroup> <authorgroup>
<author> <author>
<personname>
<firstname>Chern</firstname> <firstname>Chern</firstname>
<surname>Lee</surname> <surname>Lee</surname>
</personname>
<contrib>Rewritten by </contrib> <contrib>Rewritten by </contrib>
</author> </author>
</authorgroup> </authorgroup>
</sect2info> </info>
-->
<title>Automatic Mounts with
<application>amd</application></title>
<indexterm><primary>amd</primary></indexterm> <indexterm><primary>amd</primary></indexterm>
<indexterm> <indexterm>
<primary>automatic mounter daemon</primary> <primary>automatic mounter daemon</primary>
</indexterm> </indexterm>
<para>&man.amd.8; (the automatic mounter daemon) automatically <para>The automatic mounter daemon,
<application>amd</application>, automatically
mounts a remote file system whenever a file or directory mounts a remote file system whenever a file or directory
within that file system is accessed. Filesystems that are within that file system is accessed. File systems that are
inactive for a period of time will also be automatically inactive for a period of time will be automatically
unmounted by <application>amd</application>. unmounted by <application>amd</application>.</para>
<application>amd</application> provides an alternative to
modifying <filename>/etc/fstab</filename> to list every
client.</para>
<para><application>amd</application> operates by attaching
itself as an NFS server to the <para>This daemon provides an alternative to
modifying <filename>/etc/fstab</filename> to list every
client. It operates by attaching
itself as an <acronym>NFS</acronym> server to the
<filename>/host</filename> and <filename>/host</filename> and
<filename>/net</filename> directories. When <filename>/net</filename> directories. When
a file is accessed within one of these directories, a file is accessed within one of these directories,
<application>amd</application> looks up the corresponding <application>amd</application> looks up the corresponding
remote mount and automatically mounts it. remote mount and automatically mounts it.
<filename>/net</filename> is used to mount an exported file <filename>/net</filename> is used to mount an exported file
system from an <acronym>IP</acronym> address, while system from an <acronym>IP</acronym> address while
<filename>/host</filename> is used to mount an export from a <filename>/host</filename> is used to mount an export from a
remote hostname.</para> remote hostname. For instance, an attempt to access a file within
<para>For instance, an attempt to access a file within
<filename>/host/foobar/usr</filename> would tell <filename>/host/foobar/usr</filename> would tell
<application>amd</application> to mount the <application>amd</application> to mount the
<filename>/usr</filename> export on the host <filename>/usr</filename> export on the host
@ -897,7 +860,7 @@ rpc_statd_enable="YES"</programlisting>
<title>Mounting an Export with <title>Mounting an Export with
<application>amd</application></title> <application>amd</application></title>
<para><command>showmount -e</command> shows the exported file <para>In this example, <command>showmount -e</command> shows the exported file
systems that can be mounted from the <acronym>NFS</acronym> systems that can be mounted from the <acronym>NFS</acronym>
server, <systemitem>foobar</systemitem>:</para> server, <systemitem>foobar</systemitem>:</para>
@ -917,13 +880,14 @@ Exports list on foobar:
<application>amd</application> automatically mounts the <application>amd</application> automatically mounts the
desired export.</para> desired export.</para>
<para><application>amd</application> is enabled by placing <para>To enable <application>amd</application> at boot time, add
this line in <filename>/etc/rc.conf</filename>:</para> this line to <filename>/etc/rc.conf</filename>:</para>
<programlisting>amd_enable="YES"</programlisting> <programlisting>amd_enable="YES"</programlisting>
<para>It can then be started using the &os; &man.rc.8; scripts <para>To start <application>amd</application> now:</para>
or by using the &man.service.8; command.</para>
<screen>&prompt.root; <userinput>service amd start</userinput></screen>
<para>Custom flags can be passed to <para>Custom flags can be passed to
<application>amd</application> from the <application>amd</application> from the
@ -932,10 +896,11 @@ Exports list on foobar:
<programlisting>amd_flags="-a /.amd_mnt -l syslog /host /etc/amd.map /net /etc/amd.map"</programlisting> <programlisting>amd_flags="-a /.amd_mnt -l syslog /host /etc/amd.map /net /etc/amd.map"</programlisting>
<para><filename>/etc/amd.map</filename> defines the default <para>The default options with which exports are mounted are
options with which exports are mounted. defined in <filename>/etc/amd.map</filename>.
<filename>/etc/amd.conf</filename> defines some of the more Some of the more
advanced features of <application>amd</application>.</para> advanced features of <application>amd</application> are
defined in <filename>/etc/amd.conf</filename>.</para>
<para>Consult &man.amd.8; and &man.amd.conf.5; for more <para>Consult &man.amd.8; and &man.amd.conf.5; for more
information.</para> information.</para>