linuxexpert-practice-labs/labs/lfca/1-1-linux-operating-system/README.md

LFCA 1.1: Linux operating system

Finding out what system you're on, processes and PIDs, installing and removing a package, and looking at the hardware.

Before you start

Work as root (sudo -i). Answers go in /root/lab-answers/<task>, which the lab creates. The lab starts a sleep 6000 process in the background for task 3. It notes whether tree is installed, and reset puts that back.

Tasks

1. Find the distribution, its version and the kernel version. Write them to /root/lab-answers/1, one per line: the ID and VERSION_ID from /etc/os-release, then the output of uname -r.
2. Find the program running as PID 1 with ps -ef | head, and write its name to /root/lab-answers/2.
3. Find the PID of the lab's sleep 6000 process with ps, write it to /root/lab-answers/3, and end the process with kill.
4. Install the package tree, run it, and list the files the package installed. Write the full path of the tree program from that list to /root/lab-answers/4. Then remove the package.
5. Look at the hardware with lscpu, free -h, lsblk and lspci. Write the number of CPUs that lscpu shows to /root/lab-answers/5.

Hints

• cat /etc/os-release, uname -r.
• ps -ef | head -n 3; the CMD column.
• ps -ef | grep sleep, pgrep -a sleep, kill PID.
• dnf install tree / apt install tree, rpm -ql tree or dpkg -L tree, dnf remove / apt remove.
• The CPU(s): line of lscpu.