Exam EX200 Topic 5 Question 53 Discussion

#create dir
mkdir -p /mnt/shares
groupadd sharegrp (if not existing)

#make sharegrp group the owner
chgrp sharegrp /mnt/shares
or
chown :sharegrp /mnt/shares

#grant the sharegrp and thus its members the right to read and write and block other users
chmod 2770 /mnt/shares
or
chmod 770 /mnt/shares and chmod g+s /mnt/shares

#verify
ls -ld /mnt/shares
You should see something like:
drwxrws--- 2 root sharegrp 4096 <date> /mnt/shares

1
Create the Directory /mnt/shares
Log in to the Node1 server as a root user or use a user with sudo privileges.
Create the directory:
mkdir -p /mnt/shares
2
Create the Group sharegrp
Check if the group already exists:
getent group sharegrp
If it doesn't exist, create it:
groupadd sharegrp
3
Change the Group Ownership of the Directory
Set the group ownership of /mnt/shares to sharegrp:
chown :sharegrp /mnt/shares
4
Set Directory Permissions
Use chmod to allow only members of the group to read, write, and access the directory:
chmod 2770 /mnt/shares
2: Sets the setgid bit so that files created in this directory inherit the group ownership (sharegrp).
7: Full permissions (read, write, execute) for the owner.
7: Full permissions for the group.
0: No permissions for others.
5
Verify Permissions
Check the permissions using:
ls -ld /mnt/shares
You should see something like:
drwxrws--- 2 root sharegrp 4096 <date> /mnt/shares
6
Add Users to the Group
Add users who need access to sharegrp:
usermod -aG sharegrp <username>
Replace <username> with the actual username.
Verify the user's group membership:
groups <username>
7
Test the Setup
Switch to a user who is a member of sharegrp and try creating a file:
su - <username>
touch /mnt/shares/testfile
Confirm the file's group ownership is sharegrp:
ls -l /mnt/shares/testfile
Switch to a user who is not a member of sharegrp and verify they cannot access the directory:
su - <non_group_user>
cd /mnt/shares