roachtest: cluster_creation failed

roachtest.cluster_creation [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/21275035?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/21275035?buildTab=artifacts#/kv95/enc=false/nodes=1/cpu=32/mt-shared-process) on master @ [b6ba26ae45cfe48aa668e8deeadd0519a72381fe](https://github.com/cockroachdb/cockroach/commits/b6ba26ae45cfe48aa668e8deeadd0519a72381fe):

```
test kv95/enc=false/nodes=1/cpu=32/mt-shared-process failed: (test_runner.go:998).func4: in provider: aws: failed to create instance teamcity-21275035-1773987908-44-n2cpu32-0001: failed to run: aws ec2 run-instances --associate-public-ip-address --count 1 --instance-type c7gd.8xlarge --image-id ami-05983a09f7dc1c18f --key-name teamcity-runner-ESjWpjT7ZSzeP2FZXtqOpSx_un4= --region us-east-2 --security-group-ids sg-04d72b57e29d671f1 --subnet-id subnet-0258dc9d1b6473d84 --tag-specifications ResourceType=instance,Tags=[{Key=usage,Value=roachtest},{Key=roachtest-branch,Value=master},{Key=arch,Value=arm64},{Key=created,Value=2026-03-20T07:14:29Z},{Key=Name,Value=teamcity-21275035-1773987908-44-n2cpu32-0001},{Key=Cluster,Value=teamcity-21275035-1773987908-44-n2cpu32},{Key=roachprod,Value=true},{Key=cluster,Value=teamcity-21275035-1773987908-44-n2cpu32},{Key=lifetime,Value=12h0m0s}] ResourceType=volume,Tags=[{Key=usage,Value=roachtest},{Key=roachtest-branch,Value=master},{Key=arch,Value=arm64},{Key=created,Value=2026-03-20T07:14:29Z},{Key=Name,Value=teamcity-21275035-1773987908-44-n2cpu32-0001},{Key=Cluster,Value=teamcity-21275035-1773987908-44-n2cpu32},{Key=roachprod,Value=true},{Key=cluster,Value=teamcity-21275035-1773987908-44-n2cpu32},{Key=lifetime,Value=12h0m0s}] --user-data file:///tmp/aws-startup-script947517224 --iam-instance-profile Name=roachprod-testing --block-device-mapping file:///tmp/aws-block-device-mapping1382850736 --output json: stderr:
An error occurred (MaxIOPSLimitExceeded) when calling the RunInstances operation: You have exceeded your maximum io2 IOPS limit of 100000 IOPS in this region. Please contact AWS Support to request an Elastic Block Store service limit increase.: exit status 254 [owner=test-eng]
```

Parameters:
- MetamorphicFilesystem=xfs
- MetamorphicVolumeType=io2
- cloud=aws
- coverageBuild=false
- cpu=32
- diskCount=0
- runtimeAssertionsBuild=false
Help

See: [roachtest README](https://github.com/cockroachdb/cockroach/blob/master/pkg/cmd/roachtest/README.md)

See: [How To Investigate \(internal\)](https://cockroachlabs.atlassian.net/l/c/SSSBr8c7)

Same failure on other branches

- #166139 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-26.1.2-rc]
- #166137 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.4.7-rc]
- #166136 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2.16-rc]
- #166135 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-24.3.30-rc]
- #165927 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-26.1]
- #165926 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-26.1]
- #165925 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-26.1]
- #165924 roachtest: cluster_creation failed [O-roachtest O-robot O-rsg T-testeng X-infra-flake branch-release-26.1]
- #165923 roachtest: cluster_creation failed [O-roachtest O-robot O-rsg T-testeng X-infra-flake branch-release-26.1]

/cc @cockroachdb/test-eng

[This test on roachdash](https://roachdash.crdb.dev/?filter=status:open%20t:.*cluster_creation.*&sort=title+created&display=lastcommented+project) | [Improve this report!](https://github.com/cockroachdb/cockroach/tree/master/pkg/cmd/bazci/githubpost/issues)

Jira issue: CRDB-61815

Start with pkg/cmd/roachtest/README.md, then inspect the linked TeamCity log and artifacts for the cluster_creation failure. Investigate the AWS MaxIOPSLimitExceeded error for the io2 configuration and related repeated failures; done means cluster creation no longer fails for this limit condition.

Written by the indexing model from the issue text.