roachtest: cluster_creation failed

roachtest.cluster_creation [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/21457199?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/21457199?buildTab=artifacts#/admission-control/disk-bandwidth-limiter) on release-25.4.15-rc @ [7b399e713413017b73672b6a21d1e1463b2ca97f](https://github.com/cockroachdb/cockroach/commits/7b399e713413017b73672b6a21d1e1463b2ca97f):

```
test admission-control/disk-bandwidth-limiter failed: (test_runner.go:891).func4: in provider: aws: aws create failed due to capacity for machine type m6id.2xlarge in zone(s) [us-east-2b]; suggested zone(s): [us-east-2a us-east-2c]: failed to run: aws ec2 run-instances --associate-public-ip-address --count 1 --instance-type m6id.2xlarge --image-id ami-0e83be366243f524a --key-name teamcity-runner-F27ssemgwjdwXilTTa7kGdCP9rc= --region us-east-2 --security-group-ids sg-04d72b57e29d671f1 --subnet-id subnet-0e3d146e87ebc5a2c --tag-specifications ResourceType=instance,Tags=[{Key=usage,Value=roachtest},{Key=roachtest-branch,Value=release-25-4-15-rc},{Key=cluster,Value=teamcity-21457199-1786165788-08-n2cpu8},{Key=lifetime,Value=12h0m0s},{Key=arch,Value=amd64},{Key=created,Value=2026-08-08T05:17:11Z},{Key=Name,Value=teamcity-21457199-1786165788-08-n2cpu8-0001},{Key=Cluster,Value=teamcity-21457199-1786165788-08-n2cpu8},{Key=spot,Value=true},{Key=roachprod,Value=true}] ResourceType=volume,Tags=[{Key=usage,Value=roachtest},{Key=roachtest-branch,Value=release-25-4-15-rc},{Key=cluster,Value=teamcity-21457199-1786165788-08-n2cpu8},{Key=lifetime,Value=12h0m0s},{Key=arch,Value=amd64},{Key=created,Value=2026-08-08T05:17:11Z},{Key=Name,Value=teamcity-21457199-1786165788-08-n2cpu8-0001},{Key=Cluster,Value=teamcity-21457199-1786165788-08-n2cpu8},{Key=spot,Value=true},{Key=roachprod,Value=true}] --user-data file:///tmp/aws-startup-script1143678125 --iam-instance-profile Name=roachprod-testing --block-device-mapping file:///tmp/aws-block-device-mapping2123469891 --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.2xlarge capacity in the Availability Zone you requested (us-east-2b). Our system will be working on provisioning additional capacity. You can currently get m6id.2xlarge capacity by not specifying an Availability Zone in your request or choosing us-east-2a, us-east-2c.: exit status 254 [owner=test-eng]
```

Parameters:
- cloud=aws
- coverageBuild=false
- cpu=8
- 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)

/cc @cockroachlabs/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)

Start with the roachtest README and the linked TeamCity log and artifacts, then inspect the AWS cluster-creation entry point involved in the failure. Determine how insufficient capacity in us-east-2b should be handled using the suggested zones, and verify that the admission-control/disk-bandwidth-limiter test can complete cluster creation reliably.

Written by the indexing model from the issue text.