1. What is meant by mounting a file system?Which utility is used by the system administrator to mount a file system? Write the complete command that will mount the CD drive so that you may insert a disk in the CD drive and access its contents. When exactly the root file system is mounted in a UNIX/LINUX operating system?

2. List the names of commonly used directories under the root file system and explain what each of them usually contains.

3. What is meant by a runlevel in UNIX/LINUX operating system? What are the seven different runlevel states that UNIX/LINUX operating system can run within? Explain what each state is suitable for. Write the command the check which runlevel is active in a UNIX/LINUX machine.

Explain clearly what the utility awk is meant for? Why this utility is called awk? Give at least 5 examples of awk commands that would format a file differently each time.