Provides persistent block storage volumes that can be attached to AWS EC2 instances.
EC2 instances can either be attached to an EBS volume or an instance store volume as a root device volume.
EBS volumes can be attached to an EC2 instance from the same availability zone.
You can migrate an EBS volume from one AZ to another by creating a snapshot of the volume in one AZ and then creating an EBS volume from the snapshot in another AZ.
Multiple EBS volumes can be attached to a single instance.
You cannot attach an EBS volume to multiple instances.
Each EBS volume is automatically replicated with in its availability zone proving high availability and durability.
Data is Persisted independently of the life of the EC2 instance.
EBS volume sizes and types (except magnetic EBS volumes) can be upgraded without restarting the instances.
Magnetic EBS volumes are used for more throughput than I/O
You cannot decrease the EBS volume size while the instance is running.
You can have a maximum of 5000 EBS volumes and 10000 snapshots.
EBS volume types
AWS EBS Volume Types
Snapshots
You can backup the data on your EBS volume to Amazon S3 by taking point-in-time snapshots. While EBS volumes are AZ specific, snapshots are region specific.
You will be charged for S3 data traffic and storage while creating snapshots.
Snapshots are incremental backups, which means that only the blocks on the device that have changed after your most recent snapshot are saved
When you delete a snapshot, only the data unique to that snapshot is removed.
Each snapshot contains all of the information needed to restore your data (from the moment when the snapshot was taken) to a new EBS volume.
You can track the status of your EBS snapshots through CloudWatch Events.
Snapshots can only be accessed through EC2 APIs.
Snapshots can be encrypted and copied to other regions. AMIs are created in other regions using the snapshot which can be used to launch an EC2 instance.
EBS volumes created from encrypted snapshots ate automatically encrypted and snapshots created from an encrypted EBS volume are automatically encrypted as well.
To encrypt an EBS volume or a snapshot you need an Encryption key which is called an Customer Managed Keys (CMK).
a Default CMK is created for the first time when you choose to encrypt an EBS volume.
EBS volumes with the default CMK cannot be shared with other AWS accounts. You need to create a new key in order to do this.
You can run upto 5 snapshot copy requests at a time to a single destination in one account.
You can copy snapshots available in Amazon Marketplace that are un encrypted. Only un-encrypted snapshots are shared on the marketplace.
You cannot delete the snapshot of the root volume as long as the AMI is registered. You have to unregister the AMI and then delete the snapshot
