Elastic Block Storage

Question 1

EBS concepts

Answer 1

Think virtual hard drives
Can only be used with EC2
Tied to a single AZ
Provides a variety of choices for IOPS, throughput, and cost.

Question 2

Can you create a snapshot from an EBS store?

Answer 2

Yes

Question 3

Why is instance-store faster than EBS?

Answer 3

While EBS looks and feels like a directly attached store, it’s actually disconnected and rides over the network. Instance stores are directly attached to the VM and so do not suffer latency.

Question 4

What are good use cases for instance store?

Answer 4

Local caching, buffers, and work areas.

Question 5

Why should instance stores not be used for data that requires persistence?

Answer 5

Instance stores are ephemeral, so any data added to it will not survive an instance stop, or termination, unlike EBS.

Question 6

What are some benefits of using EBS?

Answer 6

Cost-effective and easy backup strategy
Share data-sets with other users and accounts
Allows you to migrate a system to a new AZ or Region
Easily converts from unencrypted to encrypted.

Question 7

Are snapshots full replications of data, or incremental?

Answer 7

Incremental, only the new bits are added, not the entire dataset. This is reflected in billing as well.

Question 8

Since EBS snapshots are incremental, if you delete one snapshot, does that impact other snapshots?

Answer 8

No, AWS ensures consistency across all EBS snapshots, even when you delete the original snapshot. You would have to delete ALL snapshots to lose the data.