EC2 - Instance Storage

EBS (Elastic Block Store) Volume

A network drive that you can attach to your EC2 instances while they run. It allows data to persist even after the instance is terminated and can only be mounted to one instance at a time. It is bound to a specific Availability Zone.

Purpose of an EBS Volume

To provide persistent storage for EC2 instances, similar to a network USB stick.

EBS Volume Region Attachment

No, EBS volumes are bound to a specific Availability Zone and cannot be attached across regions.

AWS Free Tier for EBS

30 GB of free EBS storage of General Purpose SSD (gp2) or Magnetic storage per month.

Key Characteristics of an EBS Volume

Network-based storage (not physical) - Uses the network to communicate, which may introduce latency - Can be detached and attached to different EC2 instances quickly - Locked to a specific Availability Zone - Has provisioned capacity (GB and IOPS) - You are billed for the full provisioned capacity - Capacity can be increased over time

Moving an EBS Volume Between Availability Zones

You must first take a snapshot of the volume, then create a new volume from that snapshot in the desired Availability Zone.

Delete on Termination Attribute

It controls whether an EBS volume is deleted when its EC2 instance is terminated.

Default Behavior for Root EBS Volume

By default, the root EBS volume is deleted because the 'Delete on Termination' attribute is enabled.

Default Behavior for Non-Root EBS Volumes

By default, non-root EBS volumes are not deleted because the 'Delete on Termination' attribute is disabled.

Changing Delete on Termination Setting

It can be configured using the AWS Management Console or the AWS CLI.

Preserving Root EBS Volume After Termination

When you want to retain data or logs stored on the root volume after the instance is no longer running.

EBS Snapshot

A backup of your EBS volume at a specific point in time. It is not necessary to detach the volume to take a snapshot, but it is recommended.

Copying EBS Snapshots

Yes, EBS snapshots can be copied across Availability Zones or Regions.

EBS Snapshot Archive

A storage tier for EBS snapshots that is 75% cheaper than standard storage. It takes 24 to 72 hours to restore from the archive.

Recycle Bin for EBS Snapshots

A feature that allows you to retain deleted snapshots based on defined rules, so they can be recovered after accidental deletion.

Retention Period for Deleted EBS Snapshots

You can specify retention from 1 day to 1 year.

Fast Snapshot Restore (FSR)

A feature that fully initializes a snapshot in advance to eliminate latency during first use. This feature incurs additional cost.

Recycle Bin Protection

It protects Amazon EBS Snapshots and Amazon Machine Images (AMIs) from accidental deletions.

AMI

AMI stands for Amazon Machine Image.

What is an AMI?

A customization of an EC2 instance that includes your software, configuration, operating system, and monitoring settings.

Benefit of Using a Custom AMI

Faster boot and configuration time, since all software is pre-packaged.

AMIs Region Specificity

Yes, AMIs are built for a specific region but can be copied across regions.

Public AMI

AWS provided Amazon Machine Image.

Your own AMI

Self-created Amazon Machine Image.

AWS Marketplace AMI

Amazon Machine Image provided by third parties.

Steps to create an AMI

Start and customize an EC2 instance 2. Stop the instance (for data integrity) 3. Build an AMI (which creates EBS snapshots) 4. Launch instances from the AMI.

EBS snapshots

Creating an AMI automatically creates EBS snapshots of the instance volumes.

EC2 Instance Store

A type of high-performance hardware disk attached to an EC2 instance, offering better I/O performance than EBS.

Use of EC2 Instance Store

To get higher I/O performance for temporary or high-speed storage needs.

Data loss on EC2 Instance Store

The data is lost because Instance Store is ephemeral.

Use cases for EC2 Instance Store

Buffering, caching, scratch data, or temporary content.

Risk of using EC2 Instance Store

Data loss if the underlying hardware fails.

Responsibility for backups with EC2 Instance Store

The user is responsible for all backups and replication.

Types of EBS volumes

There are 6 types of EBS volumes.

SSD-based EBS volume types

gp2, gp3 (General Purpose SSD);io1, io2 Block Express (Provisioned IOPS SSD).

HDD-based EBS volume types

st1 (Throughput Optimized HDD), sc1 (Cold HDD).

EBS volumes characteristics

Size, Throughput, and IOPS (Input/Output Operations Per Second).

Boot volume types

gp2, gp3, io1, and io2 Block Express.

Consultation for EBS volume types

The AWS documentation.

Use cases for General Purpose SSD (gp2/gp3)

System boot volumes, virtual desktops, dev/test environments; cost-effective and low latency.

gp3 volume performance characteristics

Baseline 3,000 IOPS and 125 MiB/s throughput, up to 16,000 IOPS and 1,000 MiB/s configurable.

gp2 volume performance characteristics

3 IOPS per GB (up to 16,000 IOPS), with burst capability to 3,000 IOPS on small volumes.

Use cases for Provisioned IOPS SSD (io1/io2)

Mission-critical apps, databases, or workloads needing sustained or very high IOPS.

io1 volume specifications

4 GiB-16 TiB; up to 64,000 IOPS on Nitro EC2, 32,000 on others; IOPS can be provisioned independently.

io2 Block Express specifications

4 GiB-64 TiB; up to 256,000 IOPS with 1,000:1 IOPS:GiB ratio; sub-millisecond latency; supports multi-attach.

HDD-based EBS volumes limitations

They cannot be used as boot volumes.

Throughput Optimized HDD (st1) specs

125 GiB-16 TiB; max throughput 500 MiB/s, max IOPS 500; good for big data, log processing.

Cold HDD (sc1) specs

125 GiB-16 TiB; max throughput 250 MiB/s, max IOPS 250; good for infrequently accessed data and cost-sensitive workloads.

EBS Multi-Attach

A feature allowing the same EBS volume to be attached to multiple EC2 instances within the same Availability Zone.

EBS volume types supporting Multi-Attach

io1 and io2 family volumes.

EC2 instances sharing EBS volume limit

Up to 16 EC2 instances at a time.

Permissions with EBS Multi-Attach

Each instance has full read and write permissions to the volume.

Primary use case for EBS Multi-Attach

Not specified in the notes.

File system for EBS Multi-Attach

A cluster-aware file system (not XFS, EXT4, etc.).

Amazon EFS

A managed NFS (Network File System) that can be mounted on many EC2 instances and supports multi-AZ deployments.

EFS billing

Pay-per-use, with cost around 3x that of gp2 EBS.

Typical use cases for EFS

Content management, web serving, data sharing, and WordPress hosting.

Amazon EFS protocol

NFSv4.1 protocol.

Access control for Amazon EFS

Through security groups.

EFS compatibility with AMIs

No, it is only compatible with Linux-based AMIs.

EFS encryption method for data at rest

Encryption at rest using AWS KMS.

Type of file system for EFS

A POSIX-compliant file system with a standard Linux file API.

EFS scaling

Automatically scales to petabyte-size, supports 1000s of concurrent clients and 10+ GB/s throughput.

EFS performance modes

General Purpose (default) for latency-sensitive apps, and Max I/O for high throughput and highly parallel workloads.

EFS throughput modes

Bursting, Provisioned (fixed throughput), and Elastic (auto-scaled based on workload).

EFS Elastic Throughput

Scales throughput automatically up to 3 GiB/s for reads and 1 GiB/s for writes; ideal for unpredictable workloads.

EFS storage classes

Standard, Infrequent Access (EFS-IA), and Archive.

EFS lifecycle policies

To automatically move files to lower-cost storage tiers after N days.

Features of EFS Standard storage class

Frequently accessed files; high availability across multiple AZs; best for production.

Features of EFS Infrequent Access (EFS-IA)

Lower cost for storage with a retrieval cost; for infrequently accessed files.

EFS Archive storage class

For rarely accessed data (a few times per year); 50% cheaper.

Characteristics of EFS One Zone storage

Single AZ, good for dev/test, backup enabled by default, compatible with EFS One Zone-IA.

EFS cost savings with lifecycle management and One Zone storage

Over 90% in cost savings.

Key characteristics of EBS volumes

Attached to one EC2 instance (except io1/io2 with Multi-Attach), locked to an Availability Zone, support gp2/gp3/io1/io2 types, and can terminate with the instance (unless disabled).

IO scaling for EBS volume types

For gp2, IO scales with volume size; for gp3 and io1/io2, IO performance can be provisioned independently.

Migrating an EBS volume across Availability Zones

Take a snapshot, then restore the snapshot in a different AZ.

EBS backups during heavy traffic

Because EBS backups use IO, which can affect application performance under load.

Root EBS volume termination

The root EBS volume is deleted by default (can be changed).

Key characteristics of Amazon EFS

Supports mounting by hundreds of EC2 instances across AZs, used for shared access (e.g., WordPress), Linux-only, higher cost than EBS, supports storage tiering for cost savings.

Differences between EBS and EFS

EBS is for single-instance block storage (AZ-locked); EFS is shared file storage for many instances across AZs; EFS is Linux-only and more expensive, but scalable and sharable.