// iostat related
	driveReadsPerSec    = "reads_per_sec"
	driveReadsKBPerSec  = "reads_kb_per_sec"
	driveReadsAwait     = "reads_await"
	driveWritesPerSec   = "writes_per_sec"
	driveWritesKBPerSec = "writes_kb_per_sec"
	driveWritesAwait    = "writes_await"
	drivePercUtil       = "perc_util"
)

var (
	driveUsedBytesMD = NewGaugeMD(driveUsedBytes,
		"Total storage used on a drive in bytes", allDriveLabels...)

	totalInodes    MetricName = "total_inodes"
	readsPerSec    MetricName = "reads_per_sec"
	writesPerSec   MetricName = "writes_per_sec"
	readsKBPerSec  MetricName = "reads_kb_per_sec"
	writesKBPerSec MetricName = "writes_kb_per_sec"
	readsAwait     MetricName = "reads_await"
	writesAwait    MetricName = "writes_await"
	percUtil       MetricName = "perc_util"
	usedInodes     MetricName = "used_inodes"

	// network stats

| `minio_system_drive_writes_per_sec`            | `gauge`   | Writes per second on a drive                                       | `drive,set_index,drive_index,pool_index,server`     |
| `minio_system_drive_writes_kb_per_sec`         | `gauge`   | Kilobytes written per second on a drive                            | `drive,set_index,drive_index,pool_index,server`     |

| `minio_node_drive_reads_await`       | Average time for read requests to be served on a drive.  |
| `minio_node_drive_writes_per_sec`    | Writes per second on a drive.                            |
| `minio_node_drive_writes_kb_per_sec` | Kilobytes written per second on a drive.                 |
| `minio_node_drive_writes_await`      | Average time for write requests to be served on a drive. |