capacityNeeded := uint64(concurrent * size)
	capacity := GetTotalUsableCapacityFree(storageInfo.Disks, storageInfo)

	if capacity < capacityNeeded {
		return false, false, fmt.Sprintf("not enough usable space available to perform speedtest - expected %s, got %s",
			humanize.IBytes(capacityNeeded), humanize.IBytes(capacity))
	}

	// Verify if we can employ autotune without running out of capacity,

		Name:      totalBytes,
		Help:      "Total usable capacity online in the cluster",
		Type:      gaugeMetric,
	}
}

func getClusterCapacityUsageFreeBytesMD() MetricDescription {
	return MetricDescription{
		Namespace: clusterMetricNamespace,
		Subsystem: capacityUsableSubsystem,
		Name:      freeBytes,
		Help:      "Total free usable capacity online in the cluster",
		Type:      gaugeMetric,
	}
}

### Other notable changes

* Make the fake RESTClient usable by all the API groups, not just core. ([#35492](https://github.com/kubernetes/kubernetes/pull/35492), [@madhusudancs](https://github.com/madhusudancs))