EBS / EFS | Notion

What's an EBS Volume?

An EC2 machine loses its root volume (main drive) when it is manually terminated.
Unexpected terminations might happen from time to time (AWS would email you).
Sometimes, you need a way to store your instance data somewhere. You don't want your main data to be on your root volume, instead it should be on an attached volume.
An EBS (Elastic Block Store) Volume is a network drive you can attach to your instances while they run.
It allows your instances to persist data.

It's a network drive (i.e., not a physical drive).
- It uses the network to communicate the instance, which means there might be a bit of latency.
- It can be detached from an EC2 instance and attached to another one quickly (as long they're in the same AZ).
It's locked to an Availability Zone (AZ).
- An EBS Volume in us-east-1a cannot be attached to us-east-lb.
- To move a volume across, you first need to snapshot it.
Have a provisioned capacity (size in GBs, and IOPS).
- You get billed for all the provisioned capacity.
- You can increase the capacity of the drive over time.

EBS Volumes come in with 4 types.
- GP2 (SSD): General Purpose SSD volume that balances price and performance for a wide variety of workloads.
- IO1 (SSD): Highest-performance SSD volume for mission-critical low-latency or high-throughput workloads.
- ST1 (HDD): Low cost HDD volume designed for frequently accessed, throughput-intensive workloads.
- SC1 (HDD): Lowest cost HDD volume designed for less frequently accessed workloads.
EBS Volumes are characterized in Size | Throughput | IOPS (I/O Ops Per Sec)
Only GP2 and IO1 can be used as boot volumes.