EC2 Storage

(this post if part of the material I cover in my devops course)

Let's get a high-level view of ec2 storage.

Storage Options

• AWS EC2 comes with several storage options:
  • AWS EBS is a block-level storage that persists independently from the life of its associated instance.
  • EC2 Instance Store provides temporary block-level storage for instances. It resides physically on the hardware that is running the ec2 instance itself.
  • Amazon EFS provides scalable file storage for use with Amazon EC2. You can use an EFS file system as a common data source for workloads and applications running on multiple instances.
  • Amazon FSX provides shared network systems for other types of systems (like Windows or NetAPP) and has multiple options.
• I'd avoid listing S3 here, as it can be considerred a storage category of its own.

EC2 Root Volume

• When we launch an instance, aws creates a root volume for the instance.
• This is something that is part of the configuration of the AWS Machine Image (or AMI) we choose.
• The root volume contains the image used to boot the instance.
• Each instance has a single root volume.
• We can add storage volumes to instances when we launch them or after they are running.

EBS Backed EC2 Instances

• Instances that use Amazon EBS for the root volume automatically have an Amazon EBS volume attached.
• Such an instance can be stopped and later restarted.
• They are called EBS Backed EC2 Instances
  

  

Instance-Store backed EC2 instance

• Instances that use instance stores for the root volume automatically have one or more instance store volumes available, with one volume serving as the root volume.
• The idea is that the operating system is installed on that instance store, so the IO operations are faster.
• Such instances cannot be stopped, just terminate, and any data that is stored on the root volume is deleted.
• These instances are called Instance-Store backed EC2 instance
  

  

We'll cover some storage options in other posts.