AWS Certified Developer - Associate

EC2 - Elastic Compute Cloud

Question: How long can you reserve an EC2 Reserved Instance Answer: Either 1 year or 3 years, but not any duration in-between.

EBS - Elastic Block Store

An EBS Volume is a network drive that you can attach to your instances while they run.

They can only be mounted to one instance at a time.

They are bound to a specific availability zone.

Analogy: You can think of it like a virtual SD card.

However, where the analogy breaks down is that it's a network drive, not a physical drive, so the EC2 instance will encounter some latency when it is reading/writing data to this volume.

Delete on Termination

By default, the root EBS volume of an EC2 instance has "delete on termination" enabled

However, by default, any additional added EBS volumes will, by default, have "delete on termation" disabled.

EBS Snapshots

An EBS Snapshot is a copy of your EBS volume at a certain point in time.

You don't have to detach a volume before making a snapshot, but it is recommeded to do so.

Snapshots can be copied across Availability Zones and Regions

EBS Snapshot Archive is a cheaper place to store snapshots (75% off), but it takes 24-72 hours for the snapshots to be recovered. o

AMI - Amazon Machine Image

An AMI is a customization of an EC2 instance, with custom software, monitoring, operating system, configuration, etc.

A benefit of a custom AMI is having a faster boot with all of your necessary set-up steps built-in.

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

EC2 Instance Store

Certain types of EC2 instances can utilize an EC2 Instance Store, a physical hardware disk for high-performance situations.

Note: An EC2 Instance Store is ephemeral storage. In other words, if you terminate an EC2 Instance with an EC2 Instance Store, you lose the data on the EC2 Instance Store.

EBS Volume Type Use Cases

For a database workload, which is sensitive to storage performance and consistency, you should use a Provisioned IOPS (PIOPS) SSD such as io1.

EBS Multi-Attach

The io1/io2 family allows you to attach the same EBS volume to multiple EC2 instances, within the same availability zone.

EFS - Elastic File System

An EFS is a managed network file system (NFS) that can be mounted on multiple EC2 instances, even across different availability zones (but within a single region)

EFS is only compatible with Linux-based AMIs. (not Windows)

The file system scales automatically, so size does not need to be provisioned at launch.