kubernetes/kops · error

error modifying volume: %v

Error message

error modifying volume: %v

What it means

EC2 ModifyVolume failed while applying volume type/size/IOPS/throughput changes to an existing EBS master/etcd volume; AWS commonly rejects unsupported modifications (e.g. shrinking size, lowering IOPS below the type minimum, or unsupported type transitions).

Source

Thrown at upup/pkg/fi/cloudup/awstasks/ebsvolume.go:187

			}
		}

		if len(changes.VolumeType) > 0 ||
			changes.VolumeIops != nil ||
			changes.VolumeThroughput != nil ||
			changes.SizeGB != nil {

			request := &ec2.ModifyVolumeInput{
				VolumeId:   a.ID,
				VolumeType: e.VolumeType,
				Iops:       e.VolumeIops,
				Throughput: e.VolumeThroughput,
				Size:       e.SizeGB,
			}

			_, err := t.Cloud.EC2().ModifyVolume(ctx, request)
			if err != nil {
				return fmt.Errorf("error modifying volume: %v", err)
			}
		}
	}
	return nil
}

// getEBSVolumeTagsToDelete loops through the currently set tags and builds
// a list of tags to be deleted from the EBS Volume
func (e *EBSVolume) getEBSVolumeTagsToDelete(currentTags map[string]string) map[string]string {
	tagsToDelete := map[string]string{}
	for k, v := range currentTags {
		if _, ok := e.Tags[k]; !ok {
			tagsToDelete[k] = v
		}
	}

	return tagsToDelete
}

View on GitHub (pinned to 4c8573c808)

Solutions

1. Ensure the new size is larger than the current size (EBS cannot shrink); migrate data to a new volume instead
2. Wait 6+ hours since the last modification if the AWS rate limit hit
3. Verify the volume type supports the requested throughput/IOPS
4. Grant ec2:ModifyVolume in the IAM policy

Example fix

// before
volumeSize: 10   // shrinking from 20 is unsupported
// after
volumeSize: 40   // only grow, or create a new volume and migrate

// Only ever grow volumes; check last-modification window
desc, _ := ec2Client.DescribeVolumes(ctx, &ec2.DescribeVolumesInput{VolumeIds: []string{volID}})
v := desc.Volumes[0]
if newSize < *v.Size { return errors.New("EBS volumes cannot be shrunk") }
if v.ModifiedAt != nil && time.Since(*v.ModifiedAt) < 6*time.Hour {
    return errors.New("volume modified <6h ago; AWS limits modification frequency")
}

When it happens

Trigger: ModifyVolume fails while reconciling changes to an existing volume — requesting a smaller size (shrink unsupported), invalid size/type/throughput combination, exceeding the 1000-modify-per-6h AWS limit per volume, missing ec2:ModifyVolume permission.

Common situations: Editing the instance group's volume size downward; changing throughput on a non-gp3 volume; re-running updates too frequently hitting the once-per-6-hours modification limit.

Related errors

• error deleting Volume %q: %v
• error describing volumes: %v
• error listing volumes: %v
• found multiple Volumes with name: %s
• error creating PersistentVolume: %v

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/f0b0862cbaca81ae. Report an issue: GitHub.