OPS335 NFS Lab

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NFS and Automount

In this lab you'll set up a Fedora 16 host as an NFS (Network File System) server. Then you'll set up a Fedora 16 guest VM (Virtual Machine) that will import its /home directory from this host.

Before you begin make sure your Fedora 16 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 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	nfs	defaults	0 0
  • 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.
    • You will 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.

Part B: 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

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

Testing NFS mounts on your VM

  • Start up vm03 and login using your learnid.
  • On your host PC run and record the output of the following commands:
showmount -e
  • Now on vm03
mount | grep /home
  • 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 performt he 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 and back on the host start the nfs server.
  • 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 (*)?
  7. What is the meaning of the ampersand (&)?
  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?
  11. What boolean did you need to change in order for SE Linux to allow NFS home directories to function properly?