Amazon Elastic Block Store (EBS)

• Provides Block level storage to EC2 instances
• (however, it) offers persistent and durable data storage (which is a huge plus)
• Greater flexibility than that of instance store volumes
• EBS volumes can be attached to EC2 instances for rapidly changing data
• Used to retain valuable data due to its persistent qualities and as such can be used to store PII
• Operate as a separate service to EC2
• EBS volumes act as network attached storage devices
• Each volume can only be attached to one EC2 instance
• Multiple EBS volumes can be attached to a single EC2 instance
• Data is retained if the EC2 instance is stopped, restarted or terminated

EBS Snapshots

• Has the ability to take point-in-time snapshots of EBS Volumes as and when needed. Manual or automatic.
• Snapshots are stored in S3 and are available from all availability zones
• Incremental snapshots
• A new EBS volume can be (re)created from the snapshots and then attach that volume to the EC2 instance
• Can copy snapshot from one region to another
• Highly available - every write to an EBS volume is replicated multiple times within the same AZ of the region to help prevent complete loss of data.

EBS Volume Types

Allows you to optimise your volumes on a cost-to-performance perspective

1. SSD-backed storage - Solid State Drive
   • Suited for work with smaller blocks such as
   • Databases using transactional workloads
   • Often used for boot volumes on EC2 instances
   • Types
     • General Purpose SSD (GP2)
     • Provisioned IOS (IO1)
2. HDD-backed storage - Hard Disk Drive
   • Designed for workloads requiring a high rate of throughput (MB/s) such as
   • Big Data processing and logging information
   • Larger blocks of data
   • Types
     • Cold HDD (SC1)
     • Throughput Optimized HDD (ST1)

General Purpose SSD (GP2)

• Provides single digit ms latency
• Can burst up to 3000 IOPS

Provisioned IOPS (IO1)

• Delivers predictable performance for I/O intensive workloads
• Max IOPS possible is set to 20000

Cold HDD (SC1)

• Offers the lowest cost compared to other volume types
• Designed for large workloads accessed infrequently
• High throughput capabilities (MB/s)
• Can’t use as boot volumes for EC2 instances

Throughput Optimized HDD (ST1)

• Designed for frequently accessed data
• Suited to work with large data sets requiring throughput-intensive workloads
• Can’t use as boot volumes for EC2 instances

Encryption

• EBS offers encryption at rest and in transit
• Encryption is managed by EBS service itself
• Does so by integrating with AWS KMS
  • KMS uses customer master keys (CMK) to create data encryption keys (DEK) enabling encryption of data for AWS services such as EBS
• Any snapshot taken from an encrypted volume will also be encrypted
• Encryption is only available for certain instance types

Creating a new EBS Volume

2 ways to create from within the management console

1. During the creation of a new EC2 instance
2. As a stand alone EBS Volume Must specify which AZ that volume will exist in EBS volumes can only be attached to EC2 instances that exist within the same AZ

Changing the size of an EBS Volume

• EBS volumes are elastically scalable
• Increase the volume size via the AWS Management Console or AWS CLI
• After the increase you must extend the filesystem on the EC2 instance to utilize the additional storage

Pricing

• Unlike S3 where you’re charged based on how much space you are using, for EBS you’re charged on a monthly basis for the volume you’re provisioned

Anti-patterns

EBS is not well suited fro all storage requirements like

• Temporary storage
• Multi-instance storage access (EBS can only be attached to one EC2 instance at a time)
• Very hight durability and availability (if you need this, you’ll be better suited if you used S3 or EFS)

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