EBS 101

Question 1

What does EBS stand for?

Answer 1

Elastic Block Store

Question 2

What is Amazon EBS?

Answer 2

• think virtual hard disk drive in the cloud
• persistent block storage volumes for use with EC2 instances in AWS Cloud

Question 3

What is an EBS Snapshot?

Answer 3

A snapshot is a point in time copy of a volume

Question 4

Where are EBS Snapshots stored?

Answer 4

in S3

Question 5

Suppose you take a snapshot of a volume, then add a new file to a volume, then take a second snapshot. What is stored in the second snapshot?

Answer 5

• Snapshots are incremental – only blocks that have changed since your last snapshot are moved to S3
• So, only the new file (the delta) is stored in the second snapshot

Question 6

Can you take a snapshot of an EBS volume while the underlying EC2 instance is running?

Answer 6

• Yes, but it is not the best practice.
• To create a snapshot for EBS volumes that serve as root devices, you should stop the instance before taking the snapshot.

Question 7

Can you create an AMI from an EBS volume?

Answer 7

Yes

Question 8

Can you create an AMI from an EBS Snapshot?

Answer 8

Yes

Question 9

Can you change the size of an EBS volume on the fly?

Answer 9

Yes, including the size and storage type

Question 10

In what Availability Zone is an EBS volume stored?

Answer 10

In the same Availability zone as the EC2 instance to which it is connected

Question 11

How do you move an EC2 Instance from one Availability Zone to another?

Answer 11

1. Take a snapshot of it
2. Create an AMI from the snapshot
3. Use the AMI to launch the EC2 instance in a new AZ

Question 12

How do you move an EC2 instance from one region to another?

Answer 12

1. Take a snapshot of the EC2 instance
2. Create an AMI from the snaphsot
3. Copy the AMI from one region to the other
4. Use the copied AMI to launch the new EC2 instance in the new region

Question 13

Can an AMI in one region be used to create an EC2 Instance in a different region?

Answer 13

NO

Question 14

What is EBS Multi-Attach?

Answer 14

Allows you to attach the same EBS Volume to multiple EC2 Instances in the same AZ

ONLY available for io1 and io2 instances

Question 15

How do you attach an EBS volume in one AZ to a different EBS volume in a different AZ?

Answer 15

You Can’t

EBS volume must be in the same AZ as the EC2 instance to which it is connected

(you can try to use AMIs to create a copy of the EBS volume in a different AZ)

Question 16

What is EC2 Instance Store?

Answer 16

Physical Hard drive space available on certain EC2 instances. Good for really high performance computing

BUT, if you terminate the EC2 instance, the data is lost

Question 17

What is the maximum number of EC2 instances that can be attached to the same EBS volume using EBS Multi-Attach?

Answer 17

16

(and remember, they all have to be in the same AZ)