If you do not manage cloud resources correctly, the cost of Amazon Elastic Block Store (AWS EBS) can have a significant impact on your overall AWS spending. This high-performance block storage service is designed for use with Amazon Elastic Compute Cloud (Amazon EC2) for both throughput- and transaction-intensive workloads at any scale. It’s essential to manage Amazon EC2 instances effectively to avoid the cost of unused or over provisioned AWS EBS volumes.
There are three critical signs that you’re overspending on Amazon EBS due to unused and over provisioned AWS EBS volumes:
- Low utilization of I/O when Provisioned IOPS is the option being used.
- An AWS EBS volume left running when you stop an Amazon EC2 instance for a long time.
- An AWS EBS volume running on its own, not attached to an Amazon EC2 instance.
Based on my experience, I’ve noticed that some of the customers do not pay attention to the hidden cost of unused and over provisioned AWS EBS volumes. This cost can initially look insignificant, but over time the amount can ramp up to hundreds or thousands of dollars a month. We can take help of various tools that are designed to identify unused and over-provisioned Amazon EBS volumes and take action to eliminate this overspending before it happens.
Amazon EBS volumes are at the core of Amazon EC2 instances because this is where all the information of an operating system is stored. Without an AWS EBS volume, an Amazon EC2 instance can’t perform its functions effectively.
Importance of AWS EBS Volumes
Choosing the right Amazon EBS volume for your workload is crucial for your project and to manage cloud expenditure.
There are four types of Amazon EBS volumes. To determine the right type, consider your workload requirements, such as low-latency and throughput performance. There are two volume types for solid state drives (SSDs) and two types for hard disk drives (HDDs):
EBS General Purpose SSD (gp2) — The default volume type, designed for basic usage across a wide variety of transactional workloads, like boot volumes, low-latency interactive apps, dev and test.
Provisioned IOPS (io1) — A high-performance volume designed for latency-sensitive transactional workloads such as I/O-intensive NoSQL and relational databases like MongoDB, Cassandra, Microsoft SQL Server, MySQL, PostgreSQL, and Oracle. Io1 volumes (at $0.125/GB-month plus $0.065/provisioned IOPS) cost more than gp2 volumes (at $0.10/GB-month) because the IOPS (Input Output Per Second) of the volume can be configured and IOPS is allocated based on the size of the Amazon EBS volume that is being provisioned.
Provisioned IOPS (io2) — The io2 volumes are designed to deliver 99.999% of durability, making them 2000x more reliable than a commodity disk drive. It is provisioned for high performance databases and workload that offers very high durability. To read more, please click here.
Throughput Optimized HDD (st1) — A low-cost volume designed for frequently accessed throughput-intensive workloads, such as streaming workloads, big data, log processing, and data warehousing solutions. HDDs are less expensive than SDDs in terms of dollar per gigabyte.
Cold HDD volume (sc1) — It is the lowest-cost HDD volume, designed for less frequently accessed workloads and systems where latency is not a problem in terms of retrieval time. It is ideal for archiving solutions where the application and the files reside in one server.
In many cases, our customers attach more than one Amazon EBS volume to an Amazon EC2 instance for architectural purposes. Sometimes they use a combination of the different types of Amazon EBS volumes mentioned above, such as using gp2 for the boot volume and io2 for the database data directory, or using gp2 as a boot volume and sc1 for archiving solutions that store files used by the archiving software.
Beware of this “gotcha:” Having multiple volumes can be a problem when managing cost if you don’t know which volumes are in use and which are over provisioned. Both Amazon EC2 instances and Amazon EBS volumes have a cost attached to them.
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