Day 13 - Instance Store & User Data

Date: 2025-09-24 (Wednesday)
Status: “Done”

Lecture Notes

EC2 Advanced Features

Instance Store

  • Instance Store provides temporary block-level storage physically attached to the EC2 host.

Characteristics

  • Very high I/O and throughput
  • Data lost when instance stops or terminates
  • Cannot be detached or snapshotted

Use Cases

  • Caching or temporary data processing
  • Applications with their own redundancy or replication

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Instance Store vs EBS:

Feature Instance Store EBS
Persistence Temporary Persistent
Performance Very high High
Snapshot No Yes
Detachable No Yes
Cost Included Additional

User Data

  • User Data scripts run automatically at instance launch (once per AMI provision).
  • Linux – bash scripts
  • Windows – PowerShell scripts

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User Data Examples:

#!/bin/bash
yum update -y
yum install -y httpd
systemctl start httpd
systemctl enable httpd
echo "<h1>Hello from $(hostname -f)</h1>" > /var/www/html/index.html

Metadata

  • EC2 Instance Metadata provides details about the running instance such as private/public IP, hostname, and security groups.
  • Often used in user data scripts for dynamic configuration.

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Accessing Metadata:

# Get instance ID
curl http://169.254.169.254/latest/meta-data/instance-id

# Get public IP
curl http://169.254.169.254/latest/meta-data/public-ipv4

# Get IAM role credentials
curl http://169.254.169.254/latest/meta-data/iam/security-credentials/role-name

Hands-On Labs

Lab 07 – AWS Budgets & Cost Management

  1. Create Budget by Template → 07-01
  2. Create Cost Budget Tutorial → 07-02
  3. Create Usage Budget → 07-03
  4. Create Reserved Instance Budget → 07-04
  5. Create Savings Plans Budget → 07-05
  6. Clean Up Budgets → 07-06