EBS 101 Flashcards
EBS High Level, EBS Snapshots
What does EBS stand for?
Elastic Block Store
What is Amazon EBS?
- think virtual hard disk drive in the cloud
- persistent block storage volumes for use with EC2 instances in AWS Cloud
What is an EBS Snapshot?
A snapshot is a point in time copy of a volume
Where are EBS Snapshots stored?
in S3
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?
- 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
Can you take a snapshot of an EBS volume while the underlying EC2 instance is running?
- 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.
Can you create an AMI from an EBS volume?
Yes
Can you create an AMI from an EBS Snapshot?
Yes
Can you change the size of an EBS volume on the fly?
Yes, including the size and storage type
In what Availability Zone is an EBS volume stored?
In the same Availability zone as the EC2 instance to which it is connected
How do you move an EC2 Instance from one Availability Zone to another?
- Take a snapshot of it
- Create an AMI from the snapshot
- Use the AMI to launch the EC2 instance in a new AZ
How do you move an EC2 instance from one region to another?
- Take a snapshot of the EC2 instance
- Create an AMI from the snaphsot
- Copy the AMI from one region to the other
- Use the copied AMI to launch the new EC2 instance in the new region
Can an AMI in one region be used to create an EC2 Instance in a different region?
NO
What is EBS Multi-Attach?
Allows you to attach the same EBS Volume to multiple EC2 Instances in the same AZ
ONLY available for io1
and io2
instances
How do you attach an EBS volume in one AZ to a different EBS volume in a different AZ?
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)