roachtest: cluster_creation failed

roachtest.cluster_creation [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/21273382?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/21273382?buildTab=artifacts#/cdc/frontier-persistence-benchmark/interval=5s/tables=1/ranges=10000) on release-25.4.7-rc @ [07bef7600b8717e0a0d07cab859014692f8fe16e](https://github.com/cockroachdb/cockroach/commits/07bef7600b8717e0a0d07cab859014692f8fe16e):

```
test cdc/frontier-persistence-benchmark/interval=5s/tables=1/ranges=10000 failed: (test_runner.go:873).func4: in provider: aws: failed to run: aws ec2 run-instances --associate-public-ip-address --count 1 --instance-type m6id.4xlarge --image-id ami-0e83be366243f524a --key-name teamcity-runner-HKqPt7XmT_zlMLIEHQyjQedPZEg= --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=release-25-4-7-rc},{Key=spot,Value=true},{Key=roachprod,Value=true},{Key=cluster,Value=teamcity-21273382-1773899650-20-n4cpu16},{Key=lifetime,Value=12h0m0s},{Key=arch,Value=amd64},{Key=created,Value=2026-03-19T06:15:24Z},{Key=Name,Value=teamcity-21273382-1773899650-20-n4cpu16-0003},{Key=Cluster,Value=teamcity-21273382-1773899650-20-n4cpu16}] ResourceType=volume,Tags=[{Key=usage,Value=roachtest},{Key=roachtest-branch,Value=release-25-4-7-rc},{Key=spot,Value=true},{Key=roachprod,Value=true},{Key=cluster,Value=teamcity-21273382-1773899650-20-n4cpu16},{Key=lifetime,Value=12h0m0s},{Key=arch,Value=amd64},{Key=created,Value=2026-03-19T06:15:24Z},{Key=Name,Value=teamcity-21273382-1773899650-20-n4cpu16-0003},{Key=Cluster,Value=teamcity-21273382-1773899650-20-n4cpu16}] --user-data file:///tmp/aws-startup-script848082795 --iam-instance-profile Name=roachprod-testing --block-device-mapping file:///tmp/aws-block-device-mapping3009741351 --instance-market-options MarketType=spot,SpotOptions={SpotInstanceType=one-time,InstanceInterruptionBehavior=terminate} --output json: stderr:
An error occurred (InsufficientInstanceCapacity) when calling the RunInstances operation (reached max retries: 2): We currently do not have sufficient m6id.4xlarge capacity in the Availability Zone you requested (us-east-2a). Our system will be working on provisioning additional capacity. You can currently get m6id.4xlarge capacity by not specifying an Availability Zone in your request or choosing us-east-2b, us-east-2c.: exit status 254 [owner=test-eng]
```

Parameters:
- cloud=aws
- coverageBuild=false
- cpu=16
- runtimeAssertionsBuild=false
- ssd=0
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

- #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]
- #165922 roachtest: cluster_creation failed [O-roachtest O-robot O-rsg T-testeng X-infra-flake branch-release-26.1]
- #165921 roachtest: cluster_creation failed [O-roachtest O-robot O-rsg T-testeng X-infra-flake branch-release-26.1]
- #165920 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-61760

Start with the failure reported at test_runner.go:873 and read the roachtest README. Trace the AWS cluster-creation path for the reported EC2 InsufficientInstanceCapacity error in us-east-2a, then inspect the related failures on other branches. Done means the cluster_creation failure is addressed and the relevant roachtest behavior is verified.

Written by the indexing model from the issue text.