EBS

Amazon Elastic Block Store (EBS) 筆記。

Intro

高效能區塊儲存

• Network drive you can attach to instances while they run
• Allows instances to persist data, even after termination
• Can only be mounted to one instance at a time (CCP Level)
• Bound to a specific availability zone
• Analogy: Network USB Stick

Overview

Network Drive (Not Physical)

• Uses network to communicate with instance (some latency)
• Can be detached and attached to another instance quickly

AZ Bound

• EBS Volume in us-east-1a cannot be attached to us-east-1b
• To move across AZ, first need to snapshot it

Provisioned Capacity

• Size in GBs and IOPS
• Billed for all provisioned capacity
• Can increase capacity over time

Delete on Termination

Controls EBS behaviour when EC2 instance terminates:

• By default, root EBS volume is deleted (attribute enabled)
• By default, other attached EBS volumes are not deleted (attribute disabled)
• Can be controlled via AWS console or CLI

Use case: Preserve root volume when instance is terminated

Snapshots

• Make a backup (snapshot) of EBS volume at a point in time
• Not necessary to detach volume, but recommended
• Can copy snapshots across AZ or Region

Snapshot Features