}
	if idx+1 > len(z.serverPools) {
		return pi, errInvalidArgument
	}

	info := z.serverPools[idx].StorageInfo(context.Background())
	info.Backend = z.BackendInfo()

	usableTotal := int64(GetTotalUsableCapacity(info.Disks, info))
	usableFree := int64(GetTotalUsableCapacityFree(info.Disks, info))
	return poolSpaceInfo{
		Total: usableTotal,
		Free:  usableFree,
		Used:  usableTotal - usableFree,
	}, nil

		return
	}

	// Get capacity info when asked.
	if r.Form.Get("capacity") == "true" {
		sinfo := objectAPI.StorageInfo(ctx, false)
		dataUsageInfo.TotalCapacity = GetTotalUsableCapacity(sinfo.Disks, sinfo)
		dataUsageInfo.TotalFreeCapacity = GetTotalUsableCapacityFree(sinfo.Disks, sinfo)
		if dataUsageInfo.TotalCapacity > dataUsageInfo.TotalFreeCapacity {

			Value:       float64(GetTotalCapacityFree(storageInfo.Disks)),
		})

		metrics = append(metrics, MetricV2{
			Description: getClusterCapacityUsageBytesMD(),
			Value:       float64(GetTotalUsableCapacity(storageInfo.Disks, storageInfo)),
		})

		metrics = append(metrics, MetricV2{
			Description: getClusterCapacityUsageFreeBytesMD(),