🚀 Mastering Linux System Administration & Automation | 90 Days of DevOps - Week 2

Task 4 : Volume Management & Disk Usage

4️⃣ Volume Management & Disk Usage

• Task:

  • Create a directory /mnt/devops_data.

  • Mount a new volume (or loop device for local practice).

  • Verify using df -h and mount | grep devops_data.

Step 1: Create a Directory

sudo mkdir -p /mnt/devops_data

Why? Directories are mount points for attaching storage.

Step 2: Create a Loop Device (Virtual Disk)

sudo dd if=/dev/zero of=/loop_devops.img bs=1M count=1024
sudo mkfs.ext4 /loop_devops.img

Pro Tip: dd creates raw binary files, while mkfs formats them.

Step 3: Mount the Virtual Disk

sudo mount -o loop /loop_devops.img /mnt/devops_data

Verification:

df -h | grep devops_data  # Check disk space
mount | grep devops_data  # Confirm mount details

/loop_devops.img  969M  2.6M  900M  1% /mnt/devops_data

Task 5 : Process Management & Monitoring

5️⃣ Process Management & Monitoring

• Task:

  • Start a background process (ping google.com > ping_test.log &).

  • Use ps, top, and htop to monitor it.

  • Kill the process and verify it's gone.

Step 1: Start Background Process

ping google.com > ping_test.log &

Note: & runs the process in the background.

Step 2: Monitor with CLI Tools

• ps: ps aux | grep ping

• top: Interactive process viewer (sort with Shift+M for memory)

• htop: Colorful, user-friendly alternative (install via sudo apt install htop)

Step 3: Terminate the Process

kill -9 <PID>  # Replace with actual Process ID
pkill -f "ping google.com"  # Pattern-based kill

Verification:

ps aux | grep ping  # Should show only the grep command
ls -lh ping_test.log  # Check if file size stopped growing

6️⃣ Automate Backups with Shell Scripting

• Task:

  • Write a shell script to back up /devops_workspace as backup_$(date +%F).tar.gz.

  • Save it in /backups and schedule it using cron.

  • Make the script display a success message in green text using echo -e.

• Step 1 : Write a shell script to back up /devops_workspace as backup_$(date +%F).tar.gz.

This is the shell script that can take a periodic backup of the scripts / directories and also uploads the backup to aws s3

Step 2 : Save it in /backups and schedule it using cron.

I have scheduled a periodic backup for every minute. below is the example script for taking backup every minute.

write a command crontab -e to shcedule a cron.

By Saving the above script, we have to enter a command watch ls this command shows the live page of the entered command

This above script displays the live backup process.

🔥 Key Takeaways: ✔ Linux administration is the foundation of DevOps!
✔ Automating tasks with shell scripting boosts efficiency.
✔ Logs are gold for debugging and monitoring.
✔ Managing users, processes, and storage is essential in production environments.