bucketReplProxiedGetRequestsTotalMD = NewCounterMD(bucketReplProxiedGetRequestsTotal,
		"Number of GET requests proxied to replication target",
		bucketL, targetArnL)
	bucketReplProxiedGetTaggingRequestsFailuresMD = NewCounterMD(bucketReplProxiedGetTaggingRequestsFailures,
		"Number of failures in GET tagging requests proxied to replication target",
		bucketL, targetArnL)

		"Total inodes available on a drive", allDriveLabels...)
	driveTimeoutErrorsMD = NewCounterMD(driveTimeoutErrorsTotal,
		"Total timeout errors on a drive", allDriveLabels...)
	driveIOErrorsMD = NewCounterMD(driveIOErrorsTotal,
		"Total I/O errors on a drive", allDriveLabels...)
	driveAvailabilityErrorsMD = NewCounterMD(driveAvailabilityErrorsTotal,
		"Total availability errors (I/O errors, timeouts) on a drive",

	return prometheus.NewDesc(
		md.toPromName(namePrefix),
		md.Help,
		md.VariableLabels, extraLabels,
	)
}

// NewCounterMD - creates a new counter metric descriptor.
func NewCounterMD(name MetricName, help string, labels ...string) MetricDescriptor {
	return MetricDescriptor{
		Name:           name,
		Type:           CounterMT,
		Help:           help,