AutoFS in Linux
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Linux: How To Setup AutoFS
Installing AutoFS on Ubuntu Desktop 10.04.1
I followed most of the instructions here:
https://help.ubuntu.com/community/Autofs
First, install this on the client:
# apt-get install -y autofs
Edit the /etc/auto.master file:
/home /etc/auto.home
+auto.master
which means for the local mount point /home, use the /etc/auto.home config file.
Then edit /etc/auto.home:
* my-nfs-server:/home/&
Unmount static mounts (if any) and edit /etc/fstab (if any):
$ sudo umount /server
Remove (or comment out) their respective entries in /etc/fstab.
#server:/ /server/ nfs defaults 0 0
Reload autofs:
# /etc/init.d/autofs reload
How to test that it works:
1. Create a user on the NFS server with a home directory. Create a test file like test-
nfs.txt.
2. Create the same user (without a home dir) on the NFS client with the same user ID and
group ID (required).
3. Create a password for the new user on the NFS client.
4. Log into the NFS client as the new user and list files to see your test file.
5. This also works when you log in as the new user from the Ubuntu GUI login screen.
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Another AutoFS example configuration
Client
/etc/auto.master:
/nfs/home /etc/auto.home
+auto.master
/etc/auto.home:
* nfs-server:/nfs/home/&
Even simpler, minimal AutoFS example configuration
Client
/etc/auto.master:
/nfs /etc/auto.nfs
+auto.master
/etc/auto.nfs:
* nfs-server:/nfs/&
# service autofs restart
autofs start/running, process XXXXX
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Mounting NFS File Systems using autofs
A third option for mounting an NFS share is the use of the autofs service. Autofs uses the automount
daemon to manage your mount points by only mounting them dynamically when they are accessed.
Autofs consults the master map configuration file /etc/auto.master to determine which mount
points are defined. It then starts an automount process with the appropriate parameters for each
mount point. Each line in the master map defines a mount point and a separate map file that defines the
file systems to be mounted under this mount point. For example, the /etc/auto.misc file might
define mount points in the /misc directory; this relationship would be defined in the
/etc/auto.master file.
Each entry in auto.master has three fields. The first field is the mount point. The second field is the
location of the map file, and the third field is optional. The third field can contain information such as a
timeout value.
For example, to mount the directory /proj52 on the remote machine penguin.example.net at the
mount point /misc/myproject on your machine, add the following line to auto.master:
/misc /etc/auto.misc --timeout 60
Next, add the following line to /etc/auto.misc:
myproject -rw,soft,intr,rsize=8192,wsize=8192 penguin.example.net:/proj52
The first field in /etc/auto.misc is the name of the /misc subdirectory. This subdirectory is created
dynamically by automount. It should not actually exist on the client machine. The second field contains
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mount options such as rw for read and write access. The third field is the location of the NFS export
including the hostname and directory.
Note
The directory /misc must exist on the local file system. There should be no subdirectories in /misc on
the local file system.
To start the autofs service, at a shell prompt, type the following command:
/sbin/service autofs restart
To view the active mount points, type the following command at a shell prompt:
/sbin/service autofs status
If you modify the /etc/auto.master configuration file while autofs is running, you must tell the
automount daemon(s) to reload by typing the following command at a shell prompt:
/sbin/service autofs reload
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HOWTO Setup autofs on Fedora
With autofs, the file systems are mounted as required or on demand, and then automatically
unmounted when they have not been used for some time. This means you can have two machines
both of which mount file systems from the other and the order you boot them does not
matter as long as the remote system is not required during the boot.
Before we begin you will need a machine that is exporting some shares over NFS so see my
HOWTO install NFS on Fedora page for getting that setup first. I'll wait.
So now you know how to setup NFS and get some directories shared.
Installing the software on Fedora is as easy as any other with yum.
sudo yum install autofs
That will also install a number of configuration files into /etc and one in /etc/sysconfig.
To set up a the automounts for the NFS shares being exported by a server we need to edit the file
/etc/auto.master adding one line. Using the shares from a machine called linux32. we will be
mounting them locally in /net/linux32/
with a 10 minute (600 second) time out.
sudo nano /etc/auto.master
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/etc/auto.master
/net/linux32 /etc/auto.nfslinux32 --timeout=600
The file in the middle does not exist, yet, we are about to create it.
sudo nano /etc/auto.nfslinux32
/etc/auto.nfslinux32
home -fstype=nfs,rsize=32768,wsize=32768,intr,tcp,noatime linux32:/home
You will need a line similar to the one above for each share from linux32. The magic of
automounting is that you do not need to create all the local mount point directories yourself. they
will be created and deleted as necessary. The entry in auto.master will create the first two
directories /net and /net/linux32.
To explain the layout of auto.nfslinux32. The first parameter is the mount point on the local
machine. In this case home which means you will access the fs via /net/linux32/home. The next
parameter -fstype gives the mounting options note it is an fs type of 'nfs'.
The remaining options are from mount and fstab. Take a look at the man pages you may not
want to use these.
Make sure that the autofs service will startup at boot time. If not set it so it will.
sudo chkconfig --list autofs
autofs 0:off 1:off 2:on 3:on 4:on 5:on 6:off
sudo chkconfig autofs on
Start, stop and reload the files for autofs without rebooting using the usual service command.
sudo service autofs status
sudo service autofs stop
sudo service autofs start
sudo service autofs restart
sudo service autofs reload
Very similar automounting will be done automatically when the mount point starts with /net. I
found there were a few annoyances using the automatic configuration so I do the above.
You may like to turn on the browse mode. This does have one downside in that it means that the
auto mounts will be mounted each time you access the root directory where they are mounted.
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Edit the file /etc/sysconfig/autofs changing the BROWSE_MODE flag to "yes" and reloading
autofs
/etc/sysconfig/autofs
sudo nano /etc/sysconfig/autofs
sudo service autofs reload
Further reading
1. Man pages for autofs, auto.master, mount, umount, nfs
2. The mount & umount commands, how to mount stuff and it's options and get it unmounted
again.
3. /etc/fstab how to mount file systems automatically at boot time
4. a href="http://blogging.dragon.org.uk/index.php/mini-howtos/howto-install-nfs-of-
fedora">HOWTO install NFS on Fedora
5. /etc/hosts file IP lookups
6. /etc/hosts.allow and /etc/hosts.deny A bit of security
7. Setting up Samba/Cifs
