Day 3

Session Summary – Disk Management, Swap & Cron Jobs Timeline

00:00 – 01:05 | AWS EBS Volume Types (GP2 vs GP3)

• Introduction to IOPS (Input/Output Operations Per Second)

• GP2 vs GP3 comparison

• Performance benefits of GP3 volumes

• Creating a 50GB EBS volume

01:05 – 03:15 | Attaching Volume to EC2 Instance

• Attaching volume from AWS console

• Device naming under /dev

• Checking attached disks using:

  • lsblk

  • df

03:15 – 05:10 | Understanding Volumes vs Partitions

• Concept of block devices

• What is a partition

• Dividing a disk into smaller partitions

• Example use case: separate partitions for databases

05:10 – 07:30 | Viewing Existing Partitions

• Using lsblk to inspect disks and partitions

• Understanding partition labels like xvdf1, xvdf2

07:30 – 09:10 | Partitioning Tool: parted Utility

• Introduction to parted

• Warning about selecting correct device

• Importance of using the right block device

09:10 – 11:30 | Disk Labels: MBR vs GPT

• Differences between MBR and GPT

• Partition limits in MBR

• Why GPT is the modern standard

• Creating a GPT disk label

11:30 – 15:15 | Creating Disk Partitions

• Using mkpart to create partitions

• Naming partitions

• Defining start and end sizes

• Creating multiple partitions

15:15 – 16:20 | Reloading Partition Table

• Using partprobe

• Making partition changes persistent

• Verifying partitions with lsblk

16:20 – 18:55 | Formatting Partitions with File System

• Need for formatting before use

• File system types: ext3, ext4

• Using mkfs.ext4 to format partitions

• Understanding file system performance

18:55 – 22:40 | Mounting Partitions

• Creating mount directories

• Using mount command

• Writing data to mounted partition

• Verifying mounts with:

  • df -h

  • df -Th

22:40 – 24:30 | Disk Management Flow Recap

• Steps covered:

  • Attach volume

  • Create partition

  • Format

  • Mount

• Real-world use cases

24:30 – 28:20 | Best Practices for Data Storage

• Avoid storing app data on root volume

• Use separate volumes for databases

• Data recovery advantages

• Disk expansion vs shrinking

28:20 – 29:30 | Introduction to LVM (Logical Volume Management)

• Extending partitions dynamically

• Volume groups and logical volumes

• Use cases for LVM

29:30 – 31:20 | Persistent Mounting with fstab

• Editing /etc/fstab

• Making mounts survive reboots

• Unmounting disks with umount

Swap Memory Section

31:20 – 33:10 | Introduction to Swap Memory

• What is swap

• Using disk as temporary RAM

• When swap is useful

33:10 – 37:30 | Swappiness Configuration

• Checking swappiness value

• Impact on performance

• Recommended values:

  • General systems: default (~60)

  • Databases: lower values (5–10)

• Tuning via system configuration

Cron Job Automation Section

37:30 – 39:00 | Introduction to Cron Jobs

• Automating tasks in Linux

• Example: nightly backups

39:00 – 41:30 | Cron Syntax Explained

• crontab -e usage

• Five-field cron structure:

  • Minute

  • Hour

  • Day of month

  • Month

  • Day of week

• Examples:

  • Every minute

  • 2:30 AM daily

  • Weekend jobs

41:30 – 44:20 | Creating a Cron Job Script

• Writing a test shell script

• Making script executable

• Adding cron entry

44:20 – 47:40 | Verifying Cron Execution

• Redirecting output to log file

• Using tail -f to monitor logs

• Seeing script run every minute

47:40 – End | Session Wrap-Up

• Use cases of cron jobs

• Q&A

• Session closing