diskReserveFraction = 0.15

	// diskAssumeUnknownSize is the size to assume when an unknown size upload is requested.
	diskAssumeUnknownSize = 1 << 30

	// diskMinInodes is the minimum number of inodes we want free on a disk to perform writes.
	diskMinInodes = 1000

	// tlsClientSessionCacheSize is the cache size for client sessions.
	tlsClientSessionCacheSize = 100
)

func init() {

		Subsystem: "health",
		Name:      "erasure_set_online_drives",
		Help:      "Get the count of the online drives in this erasure set",
		Type:      gaugeMetric,
	}
}

func getClusterErasureSetHealingDrivesMD() MetricDescription {
	return MetricDescription{
		Namespace: clusterMetricNamespace,
		Subsystem: "health",
		Name:      "erasure_set_healing_drives",

func TestErasureHeal(t *testing.T) {
	for i, test := range erasureHealTests {
		if test.offDisks < test.badStaleDisks {
			// test case sanity check
			t.Fatalf("Test %d: Bad test case - number of stale drives cannot be less than number of badstale drives", i)
		}

		// create some test data
		setup, err := newErasureTestSetup(t, test.dataBlocks, test.disks-test.dataBlocks, test.blocksize)
		if err != nil {

		return config.DefaultHelpPostfix(DefaultKVS, key)
	}

	// Help provides help for config values
	Help = config.HelpKVS{
		config.HelpKV{
			Key:         Bitrot,
			Description: `perform bitrot scan on drives when checking objects during scanner` + defaultHelpPostfix(Bitrot),
			Optional:    true,
			Type:        "on|off",
		},
		config.HelpKV{
			Key:         Sleep,

			"Total number of offline drives in current MinIO server instance",
			nil, nil),
		prometheus.GaugeValue,
		float64(offlineDisks.Sum()),
	)

	// MinIO Total Disks per node
	ch <- prometheus.MustNewConstMetric(
		prometheus.NewDesc(
			prometheus.BuildFQName(minioNamespace, "drives", "total"),
			"Total number of drives for current MinIO server instance",
			nil, nil),

		if errors.Is(err, errNoHealRequired) {
			countNoHeal++
		}
		r.DiskCount += result.DiskCount
		r.SetCount += result.SetCount
		r.Before.Drives = append(r.Before.Drives, result.Before.Drives...)
		r.After.Drives = append(r.After.Drives, result.After.Drives...)
	}

	// No heal returned by all serverPools, return errNoHealRequired
	if countNoHeal == len(z.serverPools) {
		return r, errNoHealRequired
	}

	if err != nil {
		t.Fatal(err)
	}

	// Object was uploaded with 4 known bad drives, so we should still be able to lose 3 drives and still write to the object.
	erasureDisks = xl.getDisks()
	z.serverPools[0].erasureDisksMu.Lock()
	xl.getDisks = func() []StorageAPI {
		erasureDisks[7] = nil
		erasureDisks[8] = nil

			if disk == nil || !disk.IsOnline() {
				parityDrives++
				offlineDrives++
				continue
			}
		}

		if offlineDrives >= (len(storageDisks)+1)/2 {
			// if offline drives are more than 50% of the drives
			// we have no quorum, we shouldn't proceed just
			// fail at that point.
			return ObjectInfo{}, toObjectErr(errErasureWriteQuorum, bucket, object)
		}

func (e SlowDown) Error() string {
	return "Please reduce your request rate"
}

// RQErrType reason for read quorum error.
type RQErrType int

const (
	// RQInsufficientOnlineDrives - not enough online drives.
	RQInsufficientOnlineDrives RQErrType = 1 << iota
	// RQInconsistentMeta - inconsistent metadata.
	RQInconsistentMeta
)

func (t RQErrType) String() string {
	switch t {
	case RQInsufficientOnlineDrives:

func (set *erasureObjects) listObjectsToRebalance(ctx context.Context, bucketName string, fn func(entry metaCacheEntry)) error {
	disks, _ := set.getOnlineDisksWithHealing(false)
	if len(disks) == 0 {
		return fmt.Errorf("no online drives found for set with endpoints %s", set.getEndpoints())
	}

	// However many we ask, versions must exist on ~50%
	listingQuorum := (set.setDriveCount + 1) / 2

	// How to resolve partial results.