[ec2]: fix ebs io2 and gp3 size limit

[edtan-caseware]

Describe the bug

io2 has a size range from 4 GiB - 64 TiB and gp3 from 1 GiB - 64 TiB (https://docs.aws.amazon.com/ebs/latest/userguide/ebs-volume-types.html). The current max size limit in aws-cdk is incorrectly set to 16 TiB: https://github.com/aws/aws-cdk/blob/main/packages/aws-cdk-lib/aws-ec2/lib/volume.ts#L826.

Note that the gp3 limit was increased back in Sept. 2025 (https://aws.amazon.com/about-aws/whats-new/2025/09/amazon-ebs-size-provisioned-performance-gp3-volumes/)

Regression Issue

• Select this option if this issue appears to be a regression.

Last Known Working CDK Library Version

No response

Expected Behavior

aws-cdk should allow creating EBS io2 volumes larger than 16 TiB.

Current Behavior

aws-cdk fails when attempting to creating EBS io2 and gp3 volumes larger than 16 TiB.

`io2` volumes must be between 1 GiB and 16384 GiB in size.

Reproduction Steps

dataVolume = new ec2.Volume(scope, 'test', {
      volumeType: ec2.EbsDeviceVolumeType.IO2,
      iops: 3000,
      size: Size.gibibytes(25000),
      ...

Possible Solution

Update Max for io2 and gp3 to 65536 here: https://github.com/aws/aws-cdk/blob/main/packages/aws-cdk-lib/aws-ec2/lib/volume.ts#L826

Additional Information/Context

No response

AWS CDK Library version (aws-cdk-lib)

aws-cdk-lib@2.189.1

AWS CDK CLI version

2.1004.0 (build f0ad96e)

Node.js Version

v20.17.0

OS

WSL2 (ubuntu): Linux CA-PF3MQVN5 6.6.87.2-microsoft-standard-WSL2 #1 SMP PREEMPT_DYNAMIC Thu Jun 5 18:30:46 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux

Language

TypeScript

Language Version

No response

Other information

No response

[pahud]

Hi @edtan-caseware,

Thanks for filing this with the doc references and repro code.

From my review, it appears the root cause is straightforward: the CDK-side validation constants for io2 and gp3 max volume size are hardcoded to 16384 GiB (16 TiB), but AWS has since raised the actual service limits to 65536 GiB (64 TiB) for both types.

Problem at a Glance

                  User requests 25,000 GiB io2 volume
                              │
                              ▼
               ┌──────────────────────────────┐
               │  Volume.validateProps()       │
               │                              │
               │  sizeRanges[IO2].Max = 16384 │
               │  25000 > 16384 ?  ──▶  YES   │
               │                              │
               │  ──▶ ValidationError thrown   │
               └──────────────────────────────┘
                              │
                              ▼
               CDK synth fails, but AWS would
               accept this volume just fine.

The fix involves updating the Max constant from 16384 to 65536 for both io2 and gp3 in the sizeRanges map in volume.ts. There's also a matching validation in service-managed-volume.ts in the ECS module that would need the same update.

A fix for this is already up in #37049 — it updates the max size for gp3 and io2 to 65536 in both volume.ts and service-managed-volume.ts, along with the corresponding test updates. We'll get that reviewed and merged.

[pahud]

As there's no workaround I am making it a p1.