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/nfs-pub ip-of-vm3(rw,root_squash)</source>
→Investigation 1: NFS Server Setup: - fixing a typo
Make sure to double check that the file permissions have been set correctly.</li>
<li>To set the sticky bit on the directory "/nfs-pub" , use the command
<soursesource>chmod +t /nfs-pub</source></li>
<li>Edit your /etc/exports file and insert the following lines:
<source>/nfs-pub ip-of-vm1(rw,root_squash)
"ip-of-vm1" should be replaced by the actual IP address of vm1 (VM1),and "ip-of-vm3" should be replaced by the actual IP address of vm3 (VM3).</li>
<li>Enter the command
<li>Create the directory /nfs-mnt. We will use this as the mount point for the remote directory.</li>
<li>Use the mount command to attach the remote directory ('''/nfs-pub''' from vm2) into the local mount point ('''/nfs-mnt''')</li>
<li>Use commands like mount or df to chech check that the mount command executed successfully (that is, that VM2's '''/nfs-pub''' is now being treated as part of the local filesystem).</li><li>Confirm that you can access the contents of /nfs-mnt. They should be identical to VM2's '''/nfs-pub''' (because it IS VM2's '''/nfspnfs-pub'''). Note the owner and the group owner of the file passwd.S.</li>
<li>Still on VM1, copy the file '''/etc/passwd''' into the '''/nfs-mnt''' directory. Name the copy '''passwd.A.root'''.</li>
<li>Confirm that the file copied correctly. Again, make note of the owner and group owner of the file.</li>
<li>Switch to being a regular ('''non-root''') user and copy the file '''/etc/passwd''' into the '''/nfs-mnt''' directory again, this time naming the copy '''passwd.A.user'''. Again, make note of the owner and group owner of the file. Note how it differs from the ownership of the file created as root.</li>
<li>Repeat this investigation on VM3, so that it also has access the shared filesystem. Replace the A in the copied filenames with B (e.g. passwd.B.root).</li>
</ol>
==Investigation 3: File creation permission and user name mapping on NFS shares==
Create new users on the NFS server (vm2), and clients (vm1 and vm3) to study the user name mapping on NFS shares:
<ol>
<li>On the NFS server create two new users userS, and ops535 with the commands
<source>useradd -u 5001 -m userS
useradd -u 5350 -m ops535</source></li>
<li>On vm1 create two new users userA, and ops535 with the commands
<source>useradd -u 5001 -m userA
useradd -u 5350 -m ops535</source>
and use the "passwd" command to set the passwords for those users</li>.
<li>On vm1 login as userA and copy the password file to '''/nfs-mnt''', naming the copy '''passwd.A.map'''.
Confirm the copying of the file and make notes of the owner and group owner of the file.</li>
<li>Logout from userA and login as ops535. Copy the password file to /nfs-mnt, this time naming it '''passwd.A.ops'''.
Again, make notes of the owner and group owner of the file.</li>
<li>Login to the NFS server, and examine the ownership of the files you just created. Who is the owner and the group owner of the respective files?</li>
<li>On your nfs-client machine, un-mount the remote directory.
Please note that this must be done by "root" and the directory /nfs-mnt is not being used by any process.</li>
<li>On the NFS server, make the following changes to the /etc/exports file:
change
<source>/nfs-pub ip-of-vm1(rw, root_squash)</source>
to
<source>/nfs-pub ip-of-vm1(rw, no_root_squash)</source>
and re-export the directory.</li>
<li>On the client, re-mount the share directory and repeat step 3 to step 6 under the super user
account "root" and copy the file /etc/group to the share directory /nfs-mnt with the
corresponding file name.</li>
<li>un-mount the remote directory.</li>
<li>On the NFS server, change the "rw" option in the /etc/exports file to "ro" and re-export the
directory.</li>
<li>On the client, re-mount the share directory and repeat step 3 to step 6 under the super user
account "root" and copy the file /etc/hosts to the share directory /nfs-mnt with the corresponding
file name.</li>
<li>Observe how the different settings on the server affected the ownership and permissions of files created on the client side.</li>
<li>Repeat this investigation on vm3, naming the first user userB (instead of userA), and replace the A in any file names with B. When creating files, try to predict the ownership and permissions of the resulting files.</li>
</ol>
==Completing the Lab==
# What is the full path name of the nfs module file? i.e. where is it on your hard drive?
# What is the purpose of the sticky bit?
# Who is the owner of /nfs-mnt/passwd.A.root and /nfs-pub/passwd.A.root? Are they the same? Why?
# Who is the owner of the file /nfs-mnt/passwd.A.user and /nfs-pub/passwd.A.user? Are they the same? Why?
# Who is the owner of the file /nfs-mnt/passwd.A.map and /nfs-pub/passwd.A.map? Are they the same? Why and why not?
# Who is the owner of the file /nfs-mnt/passwd.A.ops and /nfs-pub/passwd.A.ops? Are they the same? Why and why not?
# Who is the owner of /nfs-mnt/group.A.root and /nfs-pub/group.A.root? Are they the same? Why?
# Did the file /nfs-mnt/hosts.A.root get created? Why or why not?
