OPS335 NFS Lab

NFS and Automount

In this lab you'll set up a Fedora 17 host as an NFS (Network File System) server. Then you'll set up a Fedora 17 guest VM (Virtual Machine) that will import its /home directory from this host.

Prerequisites
Before you begin make sure your Fedora 17 host and virtual machines are up to date (yum update).

Ensure both host and VM's have firewalls set up according to prior labs. And ensure you are using your learnid account (the first user created - this will be

critical for success)

Part A: Setting up the NFS Server on the Host

On your Fedora host machine perform the following tasks:

• edit /etc/exports so that it contains ONLY the following line (where 192.168.x.4 is the IP address of your guest VM):

 /home 192.168.x.4(rw,root_squash,insecure)

• Edit the file /etc/idmapd.conf and uncomment and change the following lines:

Verbosity = 3
Domain = <learn-id>.org

• Restart the nfs-idmap daemon.

systemctl restart nfs-idmap.service

• Start your nfs server with the command:

systemctl start nfs-server.service

• Run and record the output of the following commands:

exportfs

showmount -e

NOTE: You'll have to adjust your firewall on the host to get NFS to work. Run netstat to determine the ports needed.

Part B: Setting up the Guest VM

• Ensure the VM guest network is functioning properly. You can use the "host cbc.ca" command to see if DNS queries are being answered.
• Ensure you have full connectivity to the internet.
• Be sure to set the firewall on both your VM and host according to prior labs. Use the command iptables-save to verify.
• Install the NFS software on both vm03 and your host using the command

yum install nfs-utils

• Add the following line to the bottom of the /etc/fstab file on vm03

192.168.x.1:/home  	/home	nfs4	defaults	0 0

Warning:
Do not change any other lines in this file. Do not change any lines in /etc/fstab on your host machine. Doing so can make your machine fail to boot.

• Edit the file /etc/idmapd.conf and uncomment and change the following lines:

Verbosity = 3
Domain = <learn-id>.org

• Restart the nfs-idmap daemon.

systemctl restart nfs-idmap.service

• Check /var/log/messages for output when troubleshooting.
  • If you followed the previous labs correctly, your vm should be sending log messages to your host.
  • You may see an error here nfsdopenone: Opening /proc/net/rpc/nfs4.nametoid/channedl failed: errno 2 (No such file or directory), but that's ok.
• Logout of vm03 and shut it down.

Testing NFS mounts on your VM

• Restart vm03 and login using your learnid.

• Check that the home directory is mounted

mount | grep /home

• • If it is not, try running 'mount /home' as root.
• On vm03, create an empty file using the touch command.

touch empty_file_created_on_vm03

• Now shutdown vm03.
• Now on your host PC, run the following command:

ls -l

• You should see the file you just created on vm03.

Part C: Setting up Automount on the VM

On vm03 as root perform the following tasks:

• Comment or remove the line from /etc/fstab that you entered earlier.
• Install automount

yum install autofs

• Move the existing file /etc/auto.master:

mv /etc/auto.master /etc/auto.master.orig

• This is a great way to keep a back up in case you need to restore the file in the future. Now create another:

vi /etc/auto.master

• Add only the following line:

/home   /etc/auto.home   --timeout=60

• Create the file /etc/auto.home and add ONLY the following line:

*        -fstype=nfs,rw,nosuid,soft      192.168.x.1:/home/&

• Start autofs with the command

systemctl start autofs.service

• And ensure the service will start at boot:

systemctl enable autofs.service

• Log out of vm03.
• Restart the nfs server on your host.
• Log into vm03 using your learn account.
• Open a terminal and enter the command:

mount | grep home

• How does it differ from the previous mount?
• Create another empty file with the name

touch another_empty_file_from_vm03

• Run and record the output of the command

df -hT

• Back on the host run and record the output of:

ls -l

• You should see the files you created on vm03.
• You may encounter errors with SELinux during the lab. It is required that you leave it running. Use the following commands to determine what booleans need to be flipped.

audit2allow < /var/log/audit/audit.log
audit2why < /var/log/audit/audit.log

Completing the Lab

Answer the following questions in your log book:

1. What does the no_root_squash option for an NFS mount mean?
2. Explain the meaning of the defaults option to the mount command. What do the numbers mean at the end?
3. What is the function of the 'exportfs' command?
4. What is the purpose of the 'showmount' command?
5. What is the meaning of the "timeout=60" phrase:
6. What is the meaning of the asterisk (*) in the file /etc/auto.home?
7. What is the meaning of the ampersand (&) in the file /etc/auto.home?
8. What is the role of the /etc/mtab file on the host?
9. What port did you have to open?
10. What does the idmapd daemon provide?