EBS - Elastic Block Store

Think of them as a “network USB stick”

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, even after their termination.
They can only be mounted to one instance at a time (at the CCP level)
They are bound to a specific availability zone.
Free tier: 30 GB of free EBS storage of type General Purpose (SSD) or Magnetic per month
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.
An EBS Volume in us-east-1a cannot be attached to us-east-1b
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 – Delete on Termination attribute

Controls the EBS behaviour when an EC2 instance terminates.
By default, the root EBS volume is deleted (attribute enabled)
By default, any other attached EBS volume is not deleted (attribute disabled)

EBS Volumes come in 6 types:
- gp2 / gp3 (SSD): General purpose SSD volume that balances price and performance for a wide variety of workloads.
- io1 / io2 (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)
When in doubt always consult the AWS documentation – it’s good!
Only gp2/gp3 and io1/io2 can be used as boot volumes.

Cost effective storage, low-latency.
System boot volumes, Virtual desktops, Development and test environments
1 GiB - 16 TiB
gp3:
- Baseline of 3,000 IOPS and throughput of 125 MiB/s
- Can increase IOPS up to 16,000 and throughput up to 1000 MiB/s independently.
gp2:
- Small gp2 volumes can burst IOPS to 3,000
- Size of the volume and IOPS are linked, max IOPS is 16,000
- 3 IOPS per GB, means at 5,334 GB we are at the max IOPS.

Attach the same EBS volume to multiple EC2 instances in the same AZ.
Each instance has full read & write permissions to the high-performance volume.
Use case:
Achieve higher application availability in clustered Linux applications (ex: Teradata)
Applications must manage concurrent write operations.
Up to 16 EC2 Instances at a time
Must use a file system that’s cluster-aware (not XFS, EX4, etc.)

Cannot be a boot volume.

125 GiB to 16 TiB
Throughput Optimized HDD (st1)
- Big Data, Data Warehouses, Log Processing
- Max throughput 500 MiB/s – max IOPS 500
Cold HDD (sc1):
- For data that is infrequently accessed
- Scenarios where lowest cost is important
- Max throughput 250 MiB/s – max IOPS 250

When you create an encrypted EBS volume, you get the following:
- Data at rest is encrypted inside the volume.
- All the data in flight moving between the instance and the volume is encrypted.
- All snapshots are encrypted.
- All volumes created from the snapshot are encrypted.
Encryption and decryption are handled transparently (you have nothing to do)
Encryption has a minimal impact on latency
EBS Encryption leverages keys from KMS (AES-256)
Copying an unencrypted snapshot allows encryption.
Snapshots of encrypted volumes are encrypted.

Encryption: encrypt an unencrypted EBS volume
- Create an EBS snapshot of the volume.
- Encrypt the EBS snapshot (using copy)
- Create new EBS volume from the snapshot (the volume will also be encrypted)
- Now you can attach the encrypted volume to the original instance.