EC2 Elastic Block Storage – EBS
Elastic Block Storage – EBS is a block-level storage volume that is highly available, reliable and durable. It can be attached to an instance running.
EBS is recommended as a primary storage device for data that needs frequent and granular updates, such as for e.g. Running a filesystem or database
An EBS volume acts like an unformatted, raw block device that can be attached one EC2 instance at a given time
EBS volume is independent of the instance’s running life.
An EBS volume can be attached to any instance in the same Availability Zone. It can also be used as a physical hard drive.
EBS features
EBS volumes can be created in a particular AZ and attached to any instances within that AZ. You can make a snapshot of the volume and then restore it to a new volume.
EBS volumes can be back up by creating a snapshot, which is stored at S3. EBS volumes can also be created using a snapshot. A snapshot can be attached and used to create another instance in the same region.
Snapshots can be copied to other regions and restored to new volumes. This makes it easier to use multiple AWS regions to expand geographically, migrate data centers, or recover from disasters.
EBS volumes can be encrypted using the EBS encryption feature. All data at rest, disk I/O and snapshots are encrypted.
Encryption takes place on the EC2 instance, which provides encryption of data in transit from the EC2 volume to the EBS volume.
You can dynamically increase or decrease the size of the provisioned IOPS capacities, or change the type of volume on live production volumes.
General Purpose (SSD), volumes support upto 10,000 16000 IOPS, 160 250 MB/s throughput, and Provisioned (SSD), volumes support upto 20,000 64000IOPS and 320 1000MB/s throughput.
EBS Benefits
Data AvailabilityEBS volume is automatically replicated within an Availability Zone to protect data from loss caused by failure of any one hardware component.
Data persistence persists independent of the life span of an EC2 instance
It persists even if an instance is restarted or stopped.
Root EBS volume is deleted by default on Instance termination. However, the behavior can be modified using the DeleteOnTermination flag
All volumes attached to the device are retained by default until they are deleted.
Data encryption can be done with the EBS encryption feature
EBS encryption uses AES-256 256-bit Advanced Encryption Standard algorithms (AES-256), and an Amazon-managed key infrastructure.
The server hosting the EC2 instance encrypts data-in-transit between the EC2 instance and EBS storage.
Snapshots of encrypted EBS volumes can be automatically encrypted
SnapshotsEBS allows you to take snapshots (backups of any EBS volume) and then write a copy to Amazon S3, where the data is redundantly stored in multiple Availability Zones
Snapshots can also be used to create new volumes, increase their size, or replicate data across Availability zones or regions
Snapshots are incremental backups that store only the data that has changed since the last snapshot was taken.
Snapshots can be smaller than volume because the data is compressed before being saved as S3
Snapshots are saved incrementally. However, the snapshot deletion process is designed to ensure that you only retain the most recent snapshot to restore the volume.
Refer blog post @ EBS Volume Types
EBS Volume
EBS Volume Creation
EB