What is AWS EBS?
Overview
What is Amazon EBS?
Amazon Elastic Block Store is an Amazon platform that provides block-level storage that can be attached to Amazon EC2 instances. It is a Storage Area Network, or SAN, in the cloud.
Before you dive in and for more details, check out this blog post with an introduction to AWS EBS and some information on how to manage EBS volumes.
In this post, I will be discussing the concept of Amazon EBS, the way it works, some of its common uses, and presenting some notes on its performance and security.
We will be seeing how efficient and useful is this tool, and how it can solve multiple issues for companies with large scales of data, with the width of its use cases.
How does it work?
It is a simple process, you can create a volume (that can be from 1GB to 1TB of size) and then mount it on a device (ex. dev, sdj) on an instance, format it, and you would be good to go! You can perform several things on it, such as detaching it, and connecting it to a different instance, you can also snapshot the volume to AWS S3, restore it later to a different volume.
For prices of the EBS Magnetic volumes, AWS charges $0.05 per GB/month and $0.05 per 1 million I/O requests. Other options are available, for different use cases, of course.
For more info, check the official documentation.
Common Use Cases
RAID
This is used when the customer wants to achieve a higher network throughput with a much better IOP. In a scenario where the company would configure a software level RAID array. It is supported by most OSs and is used to boost the IOPS and network throughput of a volume.
Pre-Warming
It is a term for pre-initializing, which is a function that helps to achieve high speeds of throughput when a new Volume is accessed. It is an action to be done before accessing the block storage to avoid the dramatic growth of latency of an I/O operation that occurs the first time each block is accessed.
Increasing EBS Volume Size while in Use
Since the system is elastic, which means that the size, and the IOPS can be modified while working, without an issue.
To modify the instance size, the customer should stop the instance, make a snapshot of the volume, create a new volume, and attach it there. Amazon released in a tweet that an EBS volume size and type can be modified now while in an in-use state, which reduces the workload that can occur from extending attributes of a volume.
CloudWatch Events for AWS EBS
AWS automatically provides data as instance metrics and volume status checks via Amazon CloudWatch. This a state notification system that can be used to monitor the EBS volumes. It has several state notification events for volumes, such as: OK, Warning, Impaired, and Insufficient Data. A customer can configure CloudWatch alarms to initiate an SNS notification if a state change occurs.
For more uses and/or info on each of them, check this blog post.
Performance and Security
Reliability
An EBS volume has redundancy built in it, in other words, it won’t fail if an individual drive fails, or if an error occurs in in other places. This is less reliable, still, compared to the S3’s way, which stores multiple copies of the same data in different places. This means that snapshotting the data to S3 is essential on the long run, as the data will be securely saved there. But the EBS system still stores replications of the data in different Availability Zones, but as we said, within the same instance.
Performance
EBS volumes are network-attached disk storage and therefore occupy a section of the instance’s overall bandwidth. The performance exceeds the expectations, with high sequential transfer rates, reaching 120 MB per sec. Moreover, this rate can be increased by mounting several EBS volumes on one instance, which hypothetically gives an unlimited transfer rate!
Security
Encryption and access control policies deliver a strong defense-in-depth security strategy for the data stored in the system. AWS also offers a sophisticated system of encryption for the data at rest (boot and data volumes) using Amazon-managed keys or keys customers create through Amazon Key Management Service, or KMS.
For more info, check the official description.
Closing Thoughts
In conclusion, EBS is amazingly simple and practical when it comes to comparison with the size of complex options it opens. Using traditional forms of hosting seems too old to use with the existence of this powerful cloud. This tool represents a solution for many companies that need this availability, speed, security, and flexibility in the platform they are using.
References
Amazon’s EBS Explained
https://www.rightscale.com/blog/cloud-industry-insights/amazons-elastic-block-store-explained
5 Functions of EBS Volumes You’re Not Using
https://cloud.netapp.com/blog/ebs-volumes-5-lesser-known-functions
6 AWS Cloud Storage Cost Use Cases: Part 1
https://www.cloudyn.com/blog/not-only-s3-6-aws-storage-cost-use-cases-part-1/
Storage Options in the AWS Cloud: Use Cases
https://media.amazonwebservices.com/AWS_Storage_Use_Cases.pdf