return err
	}

	// Reset drivercache built using current config
	clear(config.drivercache)
	// Remove existing tier configs
	clear(config.Tiers)
	// Copy over the new tier configs
	maps.Copy(config.Tiers, newConfig.Tiers)
	config.lastRefreshedAt = UTCNow()
	return nil
}

// Save saves tier configuration onto objAPI
func (config *TierConfigMgr) Save(ctx context.Context, objAPI ObjectLayer) error {
	if objAPI == nil {

)

var (
	// error returned when remote tier already exists
	errTierAlreadyExists = AdminError{
		Code:       "XMinioAdminTierAlreadyExists",
		Message:    "Specified remote tier already exists",
		StatusCode: http.StatusConflict,
	}
	// error returned when remote tier is not found
	errTierNotFound = AdminError{
		Code:       "XMinioAdminTierNotFound",
		Message:    "Specified remote tier was not found",
		StatusCode: http.StatusNotFound,

	case madmin.Azure:
		d, err = newWarmBackendAzure(*tier.Azure, tier.Name)
	case madmin.GCS:
		d, err = newWarmBackendGCS(*tier.GCS, tier.Name)
	case madmin.MinIO:
		d, err = newWarmBackendMinIO(*tier.MinIO, tier.Name)
	default:
		return nil, errTierTypeUnsupported
	}
	if err != nil {
		tierLogIf(ctx, err)
		return nil, errTierInvalidConfig
	}

	if probe {
		if err = checkWarmBackend(ctx, d); err != nil {

	os.TransitionTier = info.Tier
	os.TransitionStatus = info.Status
	os.RemoteObject = info.Name
	os.TransitionVersionID = info.VersionID
}

// shouldRemoveRemoteObject determines if a transitioned object should be
// removed from remote tier. If remote object is to be deleted, returns the
// corresponding tier deletion journal entry and true. Otherwise returns empty
// jentry value and false.

		merged.Bins[i] = cl.Bins[i].add(cm.Bins[i])
	}

	return merged
}

// DailyAllTierStats is used to aggregate last day tier stats across MinIO servers
type DailyAllTierStats map[string]lastDayTierStats

func (l DailyAllTierStats) merge(m DailyAllTierStats) {
	for tier, st := range m {
		l[tier] = l[tier].merge(st)
	}
}

func (l DailyAllTierStats) addToTierInfo(tierInfos []madmin.TierInfo) []madmin.TierInfo {

	for tier, st := range other.Tiers {
		ats.Tiers[tier] = ats.Tiers[tier].add(st)
	}
}

func (ats *allTierStats) clone() *allTierStats {
	if ats == nil {
		return nil
	}
	dst := *ats
	dst.Tiers = make(map[string]tierStats, len(ats.Tiers))
	maps.Copy(dst.Tiers, ats.Tiers)
	return &dst
}

func (ats *allTierStats) populateStats(stats map[string]madmin.TierStats) {

		})
		metrics = append(metrics, MetricV2{
			Description:    getClusterTransitionedObjectsMD(),
			Value:          float64(st.NumObjects),
			VariableLabels: map[string]string{"tier": tier},
		})
		metrics = append(metrics, MetricV2{
			Description:    getClusterTransitionedVersionsMD(),
			Value:          float64(st.NumVersions),
			VariableLabels: map[string]string{"tier": tier},
		})
	}

Transition tiers can be added to MinIO using `mc admin tier add` command to associate a `gcs`, `s3` or `azure` bucket or prefix path on a bucket to the tier name.
Lifecycle transition rules can be applied to buckets (both versioned and un-versioned) by specifying the tier name defined above as the transition storage class for the lifecycle rule.

## Implementation

## create a warm tier instance
(minio server /tmp/xltier/{1...4}/disk{0...1} --address :9002 2>&1 >/dev/null) &

export MC_HOST_mytier="http://minioadmin:minioadmin@localhost:9002/"

./mc ready myminio

./mc mb -l myminio/bucket2
./mc mb -l mytier/tiered

## create a tier and set up ilm policy to tier immediately

		}
		sizeS := sizeSummary{}
		for _, tier := range globalTierConfigMgr.ListTiers() {
			if sizeS.tiers == nil {
				sizeS.tiers = make(map[string]tierStats)
			}
			sizeS.tiers[tier.Name] = tierStats{}
		}
		if sizeS.tiers != nil {
			sizeS.tiers[storageclass.STANDARD] = tierStats{}
			sizeS.tiers[storageclass.RRS] = tierStats{}
		}

		if err != nil {