Linux for DevOps

Priyanka — Mon, 17 Mar 2025 09:52:21 +0000

Linux for DevOps Engineers: Essential Guide

Introduction

Linux is the backbone of modern DevOps engineering. Whether you're managing servers, automating deployments, or troubleshooting infrastructure, Linux skills are essential. This guide covers Linux commands and tasks from basic to expert level, helping you navigate system administration, security, automation, and cloud environments.

Linux Commands for DevOps Engineers
System Monitoring & Performance

top - Display real-time system resource usage
htop - Interactive process viewer
uptime - Show system uptime
free -m - Display memory usage
df -h - Show disk space usage
du -sh - Get directory size
iostat - CPU and I/O statistics Process Management
ps aux - List running processes
kill - Terminate a process
pkill -9 - Kill process by name
nohup & - Run command in the background
jobs - List background processes
fg %1 - Bring job to foreground Networking
ip a - Show IP addresses
netstat -tulnp - Show open ports
ss -tulnp - Alternative to netstat
ping - Check connectivity
curl -I - Get HTTP headers
wget - Download file
traceroute - Trace network path User & Permission Management
whoami - Show current user
id - Show user ID and groups
sudo su - - Switch user
chmod 755 - Change file permissions
chown user:group - Change file owner File & Directory Operations
ls -lah - List files with details
cp -r - Copy directories
mv - Move or rename files
rm -rf - Remove directory
find /path -name "file.txt" - Search file by name
grep "pattern" file.txt - Search inside files Package Management
apt update && apt upgrade -y - Update (Debian/Ubuntu)
yum update -y - Update (RHEL/CentOS)
dnf install - Install package (Fedora) Log Management
tail -f /var/log/syslog - View live logs
journalctl -xe - View system logs SSH & Remote Access
ssh user@host - Connect via SSH
scp file user@host:/path - Copy file via SSH
rsync -avz - Sync files

Practical Challenges & Solutions

Challenge 1: System Monitoring & Optimization
Q1: How do you find the process consuming the most CPU?
Use top or htop and check the column with the highest CPU usage.
Q2: How do you check free memory on a system?
Run free -m to see available and used memory.
Q3: How do you determine which directory is consuming the most space?
Use du -sh * | sort -hr to sort directories by size.

Challenge 2: Process & Job Management
Q1: How do you list all running processes?
Solution: Run ps aux to view all active processes.
Q2: How do you kill a process by its name?
Solution: Use pkill -9 to terminate it.
Q3: How do you bring a background job to the foreground?
Solution: Use fg % to move the job to the foreground.

Challenge 3: Networking & Connectivity
Q1: How do you find the system's IP address?
Solution: Run ip a to display network interfaces and their IP addresses.
Q2: How do you check which ports are open?
Solution: Use netstat -tulnp or ss -tulnp to list listening ports.
Q3: How do you download a file from the internet?
Solution: Use wget or curl -O .

Challenge 4: User & File Permissions
Q1: How do you create a new user and switch to it?
Run sudo useradd and then su - .
Q2: How do you give a file read, write, and execute permissions for its owner?
Use chmod 700 to set the correct permissions.
Q3: How do you change the ownership of a file?
Run chown user:group to assign a new owner.

Challenge 5: Remote Access & File Transfer
Q1: How do you connect to a remote server using SSH?
Use ssh user@host.
Q2: How do you securely transfer a file to a remote server?
Use scp user@host:/path.
Q3: How do you synchronize a local directory with a remote one?
Run rsync -avz to copy only changes.

DEV Community: Priyanka

Linux for DevOps

Linux for DevOps Engineers: Essential Guide

Introduction

Practical Challenges & Solutions