What’s New in 2025

Key Updates and Changes

• GP3 Now Standard: GP3 volumes offer 20% cost savings over GP2 with independent IOPS/throughput provisioning
• IO2 Block Express: Supports up to 256,000 IOPS and 4,000 MB/s throughput
• Multi-Attach Support: IO2 volumes can now attach to multiple EC2 instances simultaneously
• Enhanced Durability: IO2 offers 99.999% durability vs IO1’s 99.9%
• Elastic Volumes: Modify volume type, size, or performance without downtime

Migration and Cost Optimization

• GP2 to GP3: Save 20% per GB with better baseline performance (3,000 IOPS, 125 MB/s)
• IO1 to IO2: Get 500 IOPS per GB (vs 50 for IO1) at similar pricing
• Volume Modification: Changes typically complete within 6 hours for 1TB volumes

Getting the most bang for your buck with AWS Elastic Block Store (EBS)

Understanding what AWS/EC2 provides for provisioning on-demand storage is critical for DevOps. Companies waste tons by over provisioning AWS. In 2025, with GP3 volumes and IO2 Block Express, there are more opportunities than ever to optimize costs while improving performance.

Amazon Elastic Block Store

Amazon Web Services (AWS) provides Amazon Elastic Block Store (Amazon EBS) for EC2 instance storage. EBS is the virtual hard drives and SSDs for your servers running in the cloud. Amazon EBS volumes are automatically replicated, and it is easy to take snapshots of volumes to back them up in a known state. The replication happens within an availability zone (AZ).

AWS EBS has lots of advantages like reliability, snapshotting, and resizing.

AWS provides four volume types. It provides two types of Hard Disk Drives (HDD), and two types of SSDs. Volumes differ in price and performance. An EC2 instance can have many volumes attached to it, just like a server can have many drives. In 2025, IO2 volumes support Multi-Attach, allowing attachment to multiple EC2 instances simultaneously. If you wanted to share files between EC2 instances, you can also use Amazon Elastic File System or S3.

EBS Volumes Types

There are many types of volumes. Different types have different performance characteristics. The trick is to pick the most cost-efficient for the workload of your service.

Magnetic Volumes - Hard Disk Drives (HDD)

Magnetic volumes have the lowest performance for random access. However, they have the least cost per gigabyte. But, they have the highest access for throughput (500 MB/s) for sequential access. Magnetic volumes average 100 IOPS, but can burst to hundreds of IOPS.

IOPS are Input/output operations per second (pronounced eye-ops). IOPS are used to characterize storage devices.

Services like Kafka which writes to a transaction log in long streams, and databases which use log structured storage or an approximate of that using some sort of log structured merge tree (examples LevelDB, RocksDB, Cassandra) might do well with HDD EBS - Magnetic volumes. Application that might employ streaming, or less operations per second but larger writes could actually benefit from using HDDs throughput performance.

In general, magnetic volumes do best with sequential operations like:

• streaming workloads which require cost effective, fast, consistent I/O
• big data
• data warehouses
• log processing
• Databases that employ log structured merge tree

Magnetic volumes can’t be used as a boot volume.

There are two types of HDD - Magnetic Volumes:

• st1 - Throughput Optimized HDD (500 MB/s max throughput)
• sc1 - Cold HDD and most cost effective (250 MB/s max throughput)

General-Purpose SSD (gp3) - The 2025 Standard

GP3 volumes are now the recommended default for most workloads in 2025. Unlike GP2, GP3 provides:

• Baseline Performance: 3,000 IOPS and 125 MB/s regardless of volume size
• Independent Scaling: Provision up to 16,000 IOPS and 1,000 MB/s independently of storage size
• Cost Savings: 20% lower price per GB compared to GP2
• No Credit System: Consistent performance without IOPS credit accumulation

GP3 is ideal for:

• Development and test environments
• Boot volumes
• Virtual desktops
• Medium-sized databases
• Most general-purpose workloads

The top performance of GP3 is four times faster than maximum throughput of GP2 volumes.

General-Purpose SSD (gp2) - Legacy

GP2 volumes are still available but should be migrated to GP3 for cost savings. GP2 characteristics:

• Performance of 3 IOPS per GB provisioned, capped at 10,000 IOPS
• Volumes under 1 TB burst to 3,000 IOPS using credit system
• Sizes range from 1 GB to 16 TB

Migration from GP2 to GP3 can be done without downtime using Elastic Volumes.

Provisioned IOPS SSD (io2) - High Performance

IO2 volumes are the evolution of IO1, offering:

• Higher Durability: 99.999% annual failure rate (vs 99.9% for IO1)
• Better IOPS Density: 500 IOPS per GB (vs 50 for IO1)
• Multi-Attach: Can be attached to up to 16 Nitro-based instances
• Performance: Up to 64,000 IOPS for most instance types

Provisioned IOPS SSD (io2 Block Express) - Ultra High Performance

IO2 Block Express is the highest performance EBS option:

• Maximum IOPS: 256,000 IOPS
• Maximum Throughput: 4,000 MB/s
• Sub-millisecond latency
• Ideal for: SAP HANA, Oracle, Microsoft SQL Server, and other enterprise applications

Use cases for IO2/IO2 Block Express:

• Mission critical business applications that require sustained IOPS performance
• Large-scale databases with high-volume workloads
• Applications requiring consistent sub-millisecond latency

Cost Optimization Example

For a 1TB volume requiring 10,000 IOPS:

GP2 Option: Cannot achieve 10,000 IOPS (limited to 3,000 IOPS for 1TB)

GP3 Option:

• Storage: 1,000 GB × $0.08 = $80/month
• Additional IOPS: 7,000 × $0.005 = $35/month
• Total: $115/month

IO2 Option:

• Storage: 1,000 GB × $0.125 = $125/month
• IOPS included (500 IOPS/GB provides 500,000 IOPS)
• Total: $125/month

For this scenario, GP3 provides the best value while meeting performance requirements.

We hope this information is helpful. Check out our Casandra consulting and Kafka consulting. We specialize in AWS DevOps Automation for Cassandra and Kafka.

RAID

AWS allows configuring EBS volumes into RAID. EBS volumes can be setup in RAID 0 (stripe multiple volumes together) configuration for even more throughput and size. RAID 0 volume capacity is the sum of the capacities of the disks mounted. RAID 0 does not provide added redundancy for disk failures. Striping distributes the data of files among all disks mounted. In general, this speeds read and write operations almost by a factor number of disks mounted into a RAID 0 set. Increased throughput (and size for EBS) is the big benefit of RAID 0.

Note: With GP3’s ability to scale IOPS and throughput independently, RAID 0 configurations are less commonly needed in 2025.

Striping a group of volumes for RAID 0

#!/bin/bash
exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1
echo BEGIN

#Raid if multiple devices are mapped
if [ -e '/dev/nvme1n1' ] && [ -e '/dev/nvme2n1' ] ; then
 yum -y install mdadm
 # For Nitro instances, NVMe devices are used
 yes | mdadm --create /dev/md0 --level=0 --name=RAID0 --raid-devices=2 /dev/nvme1n1 /dev/nvme2n1
 mkfs.xfs -L RAID0 /dev/md0
 mount LABEL=RAID0 /mnt
 # update fstab
 echo "LABEL=RAID0       /mnt/   xfs    defaults,nofail,noatime        0       2" >> /etc/fstab
 mount -a
fi

Performance testing and monitoring

The best way to make an educated guess to pick the right EBS is to know your tool. If you are deploying Kafka or Cassandra or MongoDB then you must understand how to configure the tool and EBS to get the most bang for the buck. When in doubt, test.

You can make educated guesses about which EBS will fit your application or service the best. However using Amazon CloudWatch and watching the IOPs and IO throughput while load testing or watching production workloads could be the quickest way to to pick the best EBS volume type and get the most bang for your buck.

In 2025, CloudWatch provides enhanced EBS metrics including:

• BurstBalance (for GP2 volumes still in use)
• VolumeThroughputPercentage
• VolumeConsumedReadWriteOps
• VolumeQueueLength

This can help you decide whether to use GP3, IO2, HDDs (st1 or sc1), or configure RAID 0. There is no point in overpaying, and you do not want a laggy service or application that do not meet their SLAs.

EBS Performance Best Practices for 2025

1. Start with GP3: Unless you have specific requirements, GP3 offers the best price/performance
2. Monitor Before Upgrading: Use CloudWatch to verify you need higher performance before moving to IO2
3. Use EBS-Optimized Instances: Ensure your EC2 instance type supports EBS optimization
4. Consider Instance Store: For temporary data, instance store SSDs can provide better performance
5. Enable Encryption: EBS encryption has minimal performance impact with modern instances

Cloudurable provides Cassandra training, Cassandra consulting, Cassandra support and helps setting up Cassandra clusters in AWS.

Slide deck that covers configuring AWS Cassandra to use certain types of EBS volumes

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