932
edits
Changes
m
Change of hostnames
===PART B: Examining a Problem Solved by NIS===
*Ensure your VM03 VM3 is still mounting your home directory from VM 2 using autofs. If it is not, revisit last weeks lab.
*Many of you had an issue last week when using NFS as you had differing GID & UID's between systems - when attempting to mount the home directory from the VM2 you received various permission issues. In case you did not experience it, we will intentionally create this issue and then correct it with NIS.
*Run the following command
*Look at the existing users on VM 3 and compare them with the same users on VM 2. Find one whose credentials differ (Specifically, a user name that exists on both machines, but has a different UID). If you have no such user, create one.
*For example on VM 3:
[root@vm03 vm3 ~]# cat /etc/passwd | grep home
nis-user:x:1000:1000::/home/nis-user:/bin/bash
paul:x:1001:1001::/home/paul:/bin/bash
*And on VM 2:
[root@fvm02 fvm2 ~]# cat /etc/passwd | grep home
paul:x:1000:1000:paul:/home/paul:/bin/bash
nis-user:x:1001:1001::/home/nis-user:/bin/bash
*While the two hosts share the same users, their UID and GID are different. This will cause a problem when mounting the home directory using NFS.
*Back on vm03 vm3 try to switch to your learnid (or other account where UID/GID differs between systems)
su <learnid>
cd ~
*You should recieve a permission denied error as the UID on the local system differs from the UID of the file owner on the remote server.
*Obtain a listing of the directories in /home:
[paul@vm03 vm3 /]# ls -l /home
drwx------. 3 nis-user nis-user 4096 Mar 11 19:13 paul
*Notice that one user's home directory shows up as being owned by a different user.
*Try to access the other user's home directory (it should show up as owned by this user):
[paul@vm03 vm3 /]# cd /home/nis-user
*You should now be successful. Obtain a directory listing. Below is some example output:
[paul@vm03 vm3 /home/nis-user]$ ll
drwxr-xr-x. 2 paul paul 4096 Mar 14 09:09 Desktop
drwxr-xr-x. 2 paul paul 4096 Feb 17 05:24 Documents
drwxr-xr-x. 2 paul paul 4096 Jan 4 10:12 Videos
*Create an empty file and do a listing again
[paul@vm03 vm3 ~]$ touch empty_from_vm03empty_from_vm3 [paul@vm03 vm3 ~]$ ll -rw-rw-r--. 1 paul paul 0 Mar 18 14:58 empty_from_vm03empty_from_vm3
drwxr-xr-x. 2 paul paul 4096 Mar 14 09:09 Desktop
drwxr-xr-x. 2 paul paul 4096 Feb 17 05:24 Documents
*Change users back to root
===Part C: Client Configuration===
*Install ypbind on your vm03vm3.* You may wish to follow the logs on vm03vm3. In addition to your normal log in, ssh from the host to vm03 vm3 and get a continuous feed from the logs with:
tail -f /var/log/messages
*Edit /etc/yp.conf adding the following line:
*Make sure autofs service is installed on your VM 3 (If you completed the nfs lab, it is). If it is not, go back and complete the NFS lab now.
*Copy the autofs files from VM3 to your VM2.
scp /etc/auto.{home,master} root@vm02vm2:/etc/
*Edit /etc/auto.master on VM2 and remove the 'etc' prefix from auto.home's path:
*You will need to look into the Makefile to determine how to add auto.home and auto.master to the list of files shared by NIS.
*After making changes to your Makefile, regenerate your maps again and run the same command as above. You should now see the file and its contents when you run ypcat auto.home.
[root@vm02 vm2 yp]# ypcat auto.home
-fstype=nfs4,rw,nosuid,soft 192.168.70.3:/home/&
*On vm03 vm3 delete the autofs files, and edit the /etc/nsswitch.conf file so that autofs consults NIS. Reboot the machine.
*When the VM comes back up, SSH and ensure auto mounting of home occurred.
===Part E: Adding the other VM's===
*When you have successfully made this change on vm03vm3, repeat these steps so that vm01 vm1 will also use NIS for user identification, and mount home directories using autofsfiles located on vm2.
**Warning: When configuring the location of the NIS server to bind to, use the ip address instead of the hostname. When the machine is booting, you have no guarantee that named starts before ypbind.