fix: admin info output and improve overall performance (#10015)

- admin info node offline check is now quicker - admin info now doesn't duplicate the code across doing the same checks for disks - rely on StorageInfo to return appropriate errors instead of calling locally. - diskID checks now return proper errors when disk not found v/s format.json missing. - add more disk states for more clarity on the underlying disk errors.
2024-10-14 11:52:56 +00:00 · 2020-07-13 09:51:07 -07:00 · 2020-07-13 09:51:07 -07:00 · e7d7d5232c
parent 1d65ef3201
commit e7d7d5232c
17 changed files with 244 additions and 372 deletions
--- a/cmd/admin-handlers.go
+++ b/cmd/admin-handlers.go
@ -1419,23 +1419,12 @@ func (a adminAPIHandlers) ServerInfoHandler(w http.ResponseWriter, r *http.Reque
 	// Fetching the Storage information, ignore any errors.
 	storageInfo, _ := objectAPI.StorageInfo(ctx, false)

-	var OnDisks int
-	var OffDisks int
 	var backend interface{}
-
 	if storageInfo.Backend.Type == BackendType(madmin.Erasure) {
-
-		for _, v := range storageInfo.Backend.OnlineDisks {
-			OnDisks += v
-		}
-		for _, v := range storageInfo.Backend.OfflineDisks {
-			OffDisks += v
-		}
-
 		backend = madmin.ErasureBackend{
 			Type:             madmin.ErasureType,
-			OnlineDisks:      OnDisks,
-			OfflineDisks:     OffDisks,
+			OnlineDisks:      storageInfo.Backend.OnlineDisks.Sum(),
+			OfflineDisks:     storageInfo.Backend.OfflineDisks.Sum(),
 			StandardSCData:   storageInfo.Backend.StandardSCData,
 			StandardSCParity: storageInfo.Backend.StandardSCParity,
 			RRSCData:         storageInfo.Backend.RRSCData,
@ -1456,38 +1445,6 @@ func (a adminAPIHandlers) ServerInfoHandler(w http.ResponseWriter, r *http.Reque
 	servers := globalNotificationSys.ServerInfo()
 	servers = append(servers, server)

-	for _, sp := range servers {
-		for i, di := range sp.Disks {
-			path := ""
-			if globalIsErasure {
-				path = di.DrivePath
-			}
-			if globalIsDistErasure {
-				path = sp.Endpoint + di.DrivePath
-			}
-			// For distributed
-			for a := range storageInfo.Backend.Sets {
-				for b := range storageInfo.Backend.Sets[a] {
-					ep := storageInfo.Backend.Sets[a][b].Endpoint
-
-					if globalIsDistErasure {
-						if strings.Replace(ep, "http://", "", -1) == path || strings.Replace(ep, "https://", "", -1) == path {
-							sp.Disks[i].State = storageInfo.Backend.Sets[a][b].State
-							sp.Disks[i].UUID = storageInfo.Backend.Sets[a][b].UUID
-						}
-					}
-					if globalIsErasure {
-						if ep == path {
-							sp.Disks[i].State = storageInfo.Backend.Sets[a][b].State
-							sp.Disks[i].UUID = storageInfo.Backend.Sets[a][b].UUID
-						}
-					}
-				}
-			}
-
-		}
-	}
-
 	domain := globalDomainNames
 	services := madmin.Services{
 		Vault:         vault,
@ -1497,6 +1454,21 @@ func (a adminAPIHandlers) ServerInfoHandler(w http.ResponseWriter, r *http.Reque
 		Notifications: notifyTarget,
 	}

+	// find all disks which belong to each respective endpoints
+	for i := range servers {
+		for _, disk := range storageInfo.Disks {
+			if strings.Contains(disk.Endpoint, servers[i].Endpoint) {
+				servers[i].Disks = append(servers[i].Disks, disk)
+			}
+		}
+	}
+	// add all the disks local to this server.
+	for _, disk := range storageInfo.Disks {
+		if disk.Endpoint == disk.DrivePath {
+			servers[len(servers)-1].Disks = append(servers[len(servers)-1].Disks, disk)
+		}
+	}
+
 	infoMsg := madmin.InfoMessage{
 		Mode:         mode,
 		Domain:       domain,
--- a/cmd/admin-server-info.go
+++ b/cmd/admin-server-info.go
@ -18,16 +18,13 @@ package cmd

 import (
 	"net/http"
-	"os"

-	"github.com/minio/minio/pkg/disk"
 	"github.com/minio/minio/pkg/madmin"
 )

 // getLocalServerProperty - returns madmin.ServerProperties for only the
 // local endpoints from given list of endpoints
 func getLocalServerProperty(endpointZones EndpointZones, r *http.Request) madmin.ServerProperties {
-	var disks []madmin.Disk
 	addr := r.Host
 	if globalIsDistErasure {
 		addr = GetLocalPeer(endpointZones)
@ -42,33 +39,14 @@ func getLocalServerProperty(endpointZones EndpointZones, r *http.Request) madmin
 			if endpoint.IsLocal {
 				// Only proceed for local endpoints
 				network[nodeName] = "online"
-				var di = madmin.Disk{
-					DrivePath: endpoint.Path,
-				}
-				diInfo, err := disk.GetInfo(endpoint.Path)
-				if err != nil {
-					if os.IsNotExist(err) || isSysErrPathNotFound(err) {
-						di.State = madmin.DriveStateMissing
-					} else {
-						di.State = madmin.DriveStateCorrupt
-					}
+				continue
+			}
+			_, present := network[nodeName]
+			if !present {
+				if err := IsServerResolvable(endpoint); err == nil {
+					network[nodeName] = "online"
 				} else {
-					di.State = madmin.DriveStateOk
-					di.DrivePath = endpoint.Path
-					di.TotalSpace = diInfo.Total
-					di.UsedSpace = diInfo.Total - diInfo.Free
-					di.Utilization = float64((diInfo.Total - diInfo.Free) / diInfo.Total * 100)
-				}
-				disks = append(disks, di)
-			} else {
-				_, present := network[nodeName]
-				if !present {
-					err := IsServerResolvable(endpoint)
-					if err == nil {
-						network[nodeName] = "online"
-					} else {
-						network[nodeName] = "offline"
-					}
+					network[nodeName] = "offline"
 				}
 			}
 		}
@ -81,6 +59,5 @@ func getLocalServerProperty(endpointZones EndpointZones, r *http.Request) madmin
 		Version:  Version,
 		CommitID: CommitID,
 		Network:  network,
-		Disks:    disks,
 	}
 }
--- a/cmd/erasure-sets.go
+++ b/cmd/erasure-sets.go
@ -395,10 +395,7 @@ func (s *erasureSets) StorageUsageInfo(ctx context.Context) StorageInfo {
 		g.Wait()

 		for _, lstorageInfo := range storageInfos {
-			storageInfo.Used = append(storageInfo.Used, lstorageInfo.Used...)
-			storageInfo.Total = append(storageInfo.Total, lstorageInfo.Total...)
-			storageInfo.Available = append(storageInfo.Available, lstorageInfo.Available...)
-			storageInfo.MountPaths = append(storageInfo.MountPaths, lstorageInfo.MountPaths...)
+			storageInfo.Disks = append(storageInfo.Disks, lstorageInfo.Disks...)
 			storageInfo.Backend.OnlineDisks = storageInfo.Backend.OnlineDisks.Merge(lstorageInfo.Backend.OnlineDisks)
 			storageInfo.Backend.OfflineDisks = storageInfo.Backend.OfflineDisks.Merge(lstorageInfo.Backend.OfflineDisks)
 		}
@ -438,10 +435,7 @@ func (s *erasureSets) StorageInfo(ctx context.Context, local bool) (StorageInfo,
 	g.Wait()

 	for _, lstorageInfo := range storageInfos {
-		storageInfo.Used = append(storageInfo.Used, lstorageInfo.Used...)
-		storageInfo.Total = append(storageInfo.Total, lstorageInfo.Total...)
-		storageInfo.Available = append(storageInfo.Available, lstorageInfo.Available...)
-		storageInfo.MountPaths = append(storageInfo.MountPaths, lstorageInfo.MountPaths...)
+		storageInfo.Disks = append(storageInfo.Disks, lstorageInfo.Disks...)
 		storageInfo.Backend.OnlineDisks = storageInfo.Backend.OnlineDisks.Merge(lstorageInfo.Backend.OnlineDisks)
 		storageInfo.Backend.OfflineDisks = storageInfo.Backend.OfflineDisks.Merge(lstorageInfo.Backend.OfflineDisks)
 	}
@ -457,57 +451,12 @@ func (s *erasureSets) StorageInfo(ctx context.Context, local bool) (StorageInfo,
 	storageInfo.Backend.RRSCData = s.drivesPerSet - rrSCParity
 	storageInfo.Backend.RRSCParity = rrSCParity

-	storageInfo.Backend.Sets = make([][]madmin.DriveInfo, s.setCount)
-	for i := range storageInfo.Backend.Sets {
-		storageInfo.Backend.Sets[i] = make([]madmin.DriveInfo, s.drivesPerSet)
-	}
-
 	if local {
 		// if local is true, we are not interested in the drive UUID info.
 		// this is called primarily by prometheus
 		return storageInfo, nil
 	}

-	for i, set := range s.sets {
-		storageDisks := set.getDisks()
-		endpointStrings := set.getEndpoints()
-		for j, storageErr := range storageInfoErrs[i] {
-			if storageDisks[j] == OfflineDisk {
-				storageInfo.Backend.Sets[i][j] = madmin.DriveInfo{
-					State:    madmin.DriveStateOffline,
-					Endpoint: endpointStrings[j],
-				}
-				continue
-			}
-			var diskID string
-			if storageErr == nil {
-				// No errors returned by storage, look for its DiskID()
-				diskID, storageErr = storageDisks[j].GetDiskID()
-			}
-			if storageErr == nil {
-				storageInfo.Backend.Sets[i][j] = madmin.DriveInfo{
-					State:    madmin.DriveStateOk,
-					Endpoint: storageDisks[j].String(),
-					UUID:     diskID,
-				}
-				continue
-			}
-			if storageErr == errUnformattedDisk {
-				storageInfo.Backend.Sets[i][j] = madmin.DriveInfo{
-					State:    madmin.DriveStateUnformatted,
-					Endpoint: storageDisks[j].String(),
-					UUID:     "",
-				}
-			} else {
-				storageInfo.Backend.Sets[i][j] = madmin.DriveInfo{
-					State:    madmin.DriveStateCorrupt,
-					Endpoint: storageDisks[j].String(),
-					UUID:     "",
-				}
-			}
-		}
-	}
-
 	var errs []error
 	for i := range s.sets {
 		errs = append(errs, storageInfoErrs[i]...)
@ -1195,8 +1144,8 @@ else
 fi
 */

-func formatsToDrivesInfo(endpoints Endpoints, formats []*formatErasureV3, sErrs []error) (beforeDrives []madmin.DriveInfo) {
-	beforeDrives = make([]madmin.DriveInfo, len(endpoints))
+func formatsToDrivesInfo(endpoints Endpoints, formats []*formatErasureV3, sErrs []error) (beforeDrives []madmin.HealDriveInfo) {
+	beforeDrives = make([]madmin.HealDriveInfo, len(endpoints))
 	// Existing formats are available (i.e. ok), so save it in
 	// result, also populate disks to be healed.
 	for i, format := range formats {
@ -1210,7 +1159,7 @@ func formatsToDrivesInfo(endpoints Endpoints, formats []*formatErasureV3, sErrs
 		case sErrs[i] == errDiskNotFound:
 			state = madmin.DriveStateOffline
 		}
-		beforeDrives[i] = madmin.DriveInfo{
+		beforeDrives[i] = madmin.HealDriveInfo{
 			UUID: func() string {
 				if format != nil {
 					return format.Erasure.This
--- a/cmd/erasure-zones.go
+++ b/cmd/erasure-zones.go
@ -149,12 +149,10 @@ func (z *erasureZones) getZonesAvailableSpace(ctx context.Context, size int64) z

 	for i, zinfo := range storageInfos {
 		var available uint64
-		for _, davailable := range zinfo.Available {
-			available += davailable
-		}
 		var total uint64
-		for _, dtotal := range zinfo.Total {
-			total += dtotal
+		for _, disk := range zinfo.Disks {
+			total += disk.TotalSpace
+			available += disk.TotalSpace - disk.UsedSpace
 		}
 		// Make sure we can fit "size" on to the disk without getting above the diskFillFraction
 		if available < uint64(size) {
@ -260,13 +258,9 @@ func (z *erasureZones) StorageInfo(ctx context.Context, local bool) (StorageInfo
 	g.Wait()

 	for _, lstorageInfo := range storageInfos {
-		storageInfo.Used = append(storageInfo.Used, lstorageInfo.Used...)
-		storageInfo.Total = append(storageInfo.Total, lstorageInfo.Total...)
-		storageInfo.Available = append(storageInfo.Available, lstorageInfo.Available...)
-		storageInfo.MountPaths = append(storageInfo.MountPaths, lstorageInfo.MountPaths...)
+		storageInfo.Disks = append(storageInfo.Disks, lstorageInfo.Disks...)
 		storageInfo.Backend.OnlineDisks = storageInfo.Backend.OnlineDisks.Merge(lstorageInfo.Backend.OnlineDisks)
 		storageInfo.Backend.OfflineDisks = storageInfo.Backend.OfflineDisks.Merge(lstorageInfo.Backend.OfflineDisks)
-		storageInfo.Backend.Sets = append(storageInfo.Backend.Sets, lstorageInfo.Backend.Sets...)
 	}

 	storageInfo.Backend.Type = storageInfos[0].Backend.Type
--- a/cmd/erasure.go
+++ b/cmd/erasure.go
@ -79,17 +79,36 @@ func (er erasureObjects) Shutdown(ctx context.Context) error {
 }

 // byDiskTotal is a collection satisfying sort.Interface.
-type byDiskTotal []DiskInfo
+type byDiskTotal []madmin.Disk

 func (d byDiskTotal) Len() int      { return len(d) }
 func (d byDiskTotal) Swap(i, j int) { d[i], d[j] = d[j], d[i] }
 func (d byDiskTotal) Less(i, j int) bool {
-	return d[i].Total < d[j].Total
+	return d[i].TotalSpace < d[j].TotalSpace
+}
+
+func diskErrToDriveState(err error) (state string) {
+	state = madmin.DriveStateUnknown
+	switch err {
+	case errDiskNotFound:
+		state = madmin.DriveStateOffline
+	case errCorruptedFormat:
+		state = madmin.DriveStateCorrupt
+	case errUnformattedDisk:
+		state = madmin.DriveStateUnformatted
+	case errDiskAccessDenied:
+		state = madmin.DriveStatePermission
+	case errFaultyDisk:
+		state = madmin.DriveStateFaulty
+	case nil:
+		state = madmin.DriveStateOk
+	}
+	return
 }

 // getDisksInfo - fetch disks info across all other storage API.
-func getDisksInfo(disks []StorageAPI, endpoints []string) (disksInfo []DiskInfo, errs []error, onlineDisks, offlineDisks madmin.BackendDisks) {
-	disksInfo = make([]DiskInfo, len(disks))
+func getDisksInfo(disks []StorageAPI, endpoints []string) (disksInfo []madmin.Disk, errs []error, onlineDisks, offlineDisks madmin.BackendDisks) {
+	disksInfo = make([]madmin.Disk, len(disks))
 	onlineDisks = make(madmin.BackendDisks)
 	offlineDisks = make(madmin.BackendDisks)

@ -107,6 +126,10 @@ func getDisksInfo(disks []StorageAPI, endpoints []string) (disksInfo []DiskInfo,
 		index := index
 		g.Go(func() error {
 			if disks[index] == OfflineDisk {
+				disksInfo[index] = madmin.Disk{
+					State:    diskErrToDriveState(errDiskNotFound),
+					Endpoint: endpoints[index],
+				}
 				// Storage disk is empty, perhaps ignored disk or not available.
 				return errDiskNotFound
 			}
@ -117,10 +140,20 @@ func getDisksInfo(disks []StorageAPI, endpoints []string) (disksInfo []DiskInfo,
 					ctx := logger.SetReqInfo(GlobalContext, reqInfo)
 					logger.LogIf(ctx, err)
 				}
-				return err
 			}
-			disksInfo[index] = info
-			return nil
+			di := madmin.Disk{
+				Endpoint:   endpoints[index],
+				DrivePath:  info.MountPath,
+				TotalSpace: info.Total,
+				UsedSpace:  info.Used,
+				UUID:       info.ID,
+				State:      diskErrToDriveState(err),
+			}
+			if info.Total > 0 {
+				di.Utilization = float64(info.Used / info.Total * 100)
+			}
+			disksInfo[index] = di
+			return err
 		}, index)
 	}

@ -146,24 +179,8 @@ func getStorageInfo(disks []StorageAPI, endpoints []string) (StorageInfo, []erro
 	// Sort so that the first element is the smallest.
 	sort.Sort(byDiskTotal(disksInfo))

-	// Combine all disks to get total usage
-	usedList := make([]uint64, len(disksInfo))
-	totalList := make([]uint64, len(disksInfo))
-	availableList := make([]uint64, len(disksInfo))
-	mountPaths := make([]string, len(disksInfo))
-
-	for i, di := range disksInfo {
-		usedList[i] = di.Used
-		totalList[i] = di.Total
-		availableList[i] = di.Free
-		mountPaths[i] = di.MountPath
-	}
-
 	storageInfo := StorageInfo{
-		Used:       usedList,
-		Total:      totalList,
-		Available:  availableList,
-		MountPaths: mountPaths,
+		Disks: disksInfo,
 	}

 	storageInfo.Backend.Type = BackendErasure
--- a/cmd/fs-v1.go
+++ b/cmd/fs-v1.go
@ -53,9 +53,6 @@ var defaultEtag = "00000000000000000000000000000000-1"
 type FSObjects struct {
 	GatewayUnsupported

-	// Disk usage metrics
-	totalUsed uint64 // ref: https://golang.org/pkg/sync/atomic/#pkg-note-BUG
-
 	// The count of concurrent calls on FSObjects API
 	activeIOCount int64
 	// The active IO count ceiling for crawling to work
@ -215,15 +212,15 @@ func (fs *FSObjects) StorageInfo(ctx context.Context, _ bool) (StorageInfo, []er
 		return StorageInfo{}, []error{err}
 	}
 	used := di.Total - di.Free
-	if !fs.diskMount {
-		used = atomic.LoadUint64(&fs.totalUsed)
-	}
-
 	storageInfo := StorageInfo{
-		Used:       []uint64{used},
-		Total:      []uint64{di.Total},
-		Available:  []uint64{di.Free},
-		MountPaths: []string{fs.fsPath},
+		Disks: []madmin.Disk{
+			{
+				TotalSpace:     di.Total,
+				UsedSpace:      used,
+				AvailableSpace: di.Free,
+				DrivePath:      fs.fsPath,
+			},
+		},
 	}
 	storageInfo.Backend.Type = BackendFS
 	return storageInfo, nil
--- a/cmd/gateway/hdfs/gateway-hdfs.go
+++ b/cmd/gateway/hdfs/gateway-hdfs.go
@ -39,6 +39,7 @@ import (
 	"github.com/minio/minio/cmd/logger"
 	"github.com/minio/minio/pkg/auth"
 	"github.com/minio/minio/pkg/env"
+	"github.com/minio/minio/pkg/madmin"
 	xnet "github.com/minio/minio/pkg/net"
 	krb "gopkg.in/jcmturner/gokrb5.v7/client"
 	"gopkg.in/jcmturner/gokrb5.v7/config"
@ -210,7 +211,9 @@ func (n *hdfsObjects) StorageInfo(ctx context.Context, _ bool) (si minio.Storage
 	if err != nil {
 		return minio.StorageInfo{}, []error{err}
 	}
-	si.Used = []uint64{fsInfo.Used}
+	si.Disks = []madmin.Disk{{
+		UsedSpace: fsInfo.Used,
+	}}
 	si.Backend.Type = minio.BackendGateway
 	si.Backend.GatewayOnline = true
 	return si, nil
--- a/cmd/metrics.go
+++ b/cmd/metrics.go
@ -464,10 +464,7 @@ func storageMetricsPrometheus(ch chan<- prometheus.Metric) {
 		float64(totalDisks.Sum()),
 	)

-	for i := 0; i < len(storageInfo.Total); i++ {
-		mountPath, total, free := storageInfo.MountPaths[i], storageInfo.Total[i],
-			storageInfo.Available[i]
-
+	for _, disk := range storageInfo.Disks {
 		// Total disk usage by the disk
 		ch <- prometheus.MustNewConstMetric(
 			prometheus.NewDesc(
@ -475,8 +472,8 @@ func storageMetricsPrometheus(ch chan<- prometheus.Metric) {
 				"Total disk storage used on the disk",
 				[]string{"disk"}, nil),
 			prometheus.GaugeValue,
-			float64(total-free),
-			mountPath,
+			float64(disk.UsedSpace),
+			disk.DrivePath,
 		)

 		// Total available space in the disk
@ -486,8 +483,8 @@ func storageMetricsPrometheus(ch chan<- prometheus.Metric) {
 				"Total available space left on the disk",
 				[]string{"disk"}, nil),
 			prometheus.GaugeValue,
-			float64(free),
-			mountPath,
+			float64(disk.AvailableSpace),
+			disk.DrivePath,
 		)

 		// Total storage space of the disk
@ -497,8 +494,8 @@ func storageMetricsPrometheus(ch chan<- prometheus.Metric) {
 				"Total space on the disk",
 				[]string{"disk"}, nil),
 			prometheus.GaugeValue,
-			float64(total),
-			mountPath,
+			float64(disk.TotalSpace),
+			disk.DrivePath,
 		)
 	}
 }
--- a/cmd/object-api-datatypes.go
+++ b/cmd/object-api-datatypes.go
@ -43,13 +43,7 @@ const (

 // StorageInfo - represents total capacity of underlying storage.
 type StorageInfo struct {
-	Used []uint64 // Used total used per disk.
-
-	Total []uint64 // Total disk space per disk.
-
-	Available []uint64 // Total disk space available per disk.
-
-	MountPaths []string // Disk mountpoints
+	Disks []madmin.Disk

 	// Backend type.
 	Backend struct {
@ -66,9 +60,6 @@ type StorageInfo struct {
 		StandardSCParity int                 // Parity disks for currently configured Standard storage class.
 		RRSCData         int                 // Data disks for currently configured Reduced Redundancy storage class.
 		RRSCParity       int                 // Parity disks for currently configured Reduced Redundancy storage class.
-
-		// List of all disk status, this is only meaningful if BackendType is Erasure.
-		Sets [][]madmin.DriveInfo
 	}
 }

--- a/cmd/prepare-storage.go
+++ b/cmd/prepare-storage.go
@ -30,7 +30,6 @@ import (
 	"github.com/minio/minio/cmd/config"
 	xhttp "github.com/minio/minio/cmd/http"
 	"github.com/minio/minio/cmd/logger"
-	"github.com/minio/minio/cmd/rest"
 	"github.com/minio/minio/pkg/sync/errgroup"
 )

@ -183,7 +182,21 @@ func IsServerResolvable(endpoint Endpoint) error {
 	}

 	httpClient := &http.Client{
-		Transport: newCustomHTTPTransport(tlsConfig, rest.DefaultRESTTimeout)(),
+		Transport:
+		// For more details about various values used here refer
+		// https://golang.org/pkg/net/http/#Transport documentation
+		&http.Transport{
+			Proxy:                 http.ProxyFromEnvironment,
+			DialContext:           xhttp.NewCustomDialContext(3 * time.Second),
+			ResponseHeaderTimeout: 5 * time.Second,
+			TLSHandshakeTimeout:   5 * time.Second,
+			ExpectContinueTimeout: 5 * time.Second,
+			TLSClientConfig:       tlsConfig,
+			// Go net/http automatically unzip if content-type is
+			// gzip disable this feature, as we are always interested
+			// in raw stream.
+			DisableCompression: true,
+		},
 	}
 	defer httpClient.CloseIdleConnections()

--- a/cmd/storage-rest-client.go
+++ b/cmd/storage-rest-client.go
@ -190,7 +190,13 @@ func (client *storageRESTClient) DiskInfo() (info DiskInfo, err error) {
 	}
 	defer http.DrainBody(respBody)
 	err = gob.NewDecoder(respBody).Decode(&info)
-	return info, err
+	if err != nil {
+		return info, err
+	}
+	if info.Error != "" {
+		return info, toStorageErr(errors.New(info.Error))
+	}
+	return info, nil
 }

 // MakeVolBulk - create multiple volumes in a bulk operation.
--- a/cmd/storage-rest-server.go
+++ b/cmd/storage-rest-server.go
@ -134,8 +134,7 @@ func (s *storageRESTServer) DiskInfoHandler(w http.ResponseWriter, r *http.Reque
 	}
 	info, err := s.storage.DiskInfo()
 	if err != nil {
-		s.writeErrorResponse(w, err)
-		return
+		info.Error = err.Error()
 	}
 	defer w.(http.Flusher).Flush()
 	gob.NewEncoder(w).Encode(info)
--- a/cmd/storage-rest_test.go
+++ b/cmd/storage-rest_test.go
@ -36,16 +36,10 @@ import (
 ///////////////////////////////////////////////////////////////////////////////

 func testStorageAPIDiskInfo(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	testCases := []struct {
 		expectErr bool
 	}{
-		{false},
+		{true},
 	}

 	for i, testCase := range testCases {
@ -55,16 +49,13 @@ func testStorageAPIDiskInfo(t *testing.T, storage StorageAPI) {
 		if expectErr != testCase.expectErr {
 			t.Fatalf("case %v: error: expected: %v, got: %v", i+1, testCase.expectErr, expectErr)
 		}
+		if err != errUnformattedDisk {
+			t.Fatalf("case %v: error: expected: %v, got: %v", i+1, errUnformattedDisk, err)
+		}
 	}
 }

 func testStorageAPIMakeVol(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	testCases := []struct {
 		volumeName string
 		expectErr  bool
@ -85,12 +76,6 @@ func testStorageAPIMakeVol(t *testing.T, storage StorageAPI) {
 }

 func testStorageAPIListVols(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	testCases := []struct {
 		volumeNames    []string
 		expectedResult []VolInfo
@ -124,12 +109,6 @@ func testStorageAPIListVols(t *testing.T, storage StorageAPI) {
 }

 func testStorageAPIStatVol(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	err := storage.MakeVol("foo")
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
@ -161,12 +140,6 @@ func testStorageAPIStatVol(t *testing.T, storage StorageAPI) {
 }

 func testStorageAPIDeleteVol(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	err := storage.MakeVol("foo")
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
@ -192,12 +165,6 @@ func testStorageAPIDeleteVol(t *testing.T, storage StorageAPI) {
 }

 func testStorageAPICheckFile(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	err := storage.MakeVol("foo")
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
@ -228,12 +195,6 @@ func testStorageAPICheckFile(t *testing.T, storage StorageAPI) {
 }

 func testStorageAPIListDir(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	err := storage.MakeVol("foo")
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
@ -271,12 +232,6 @@ func testStorageAPIListDir(t *testing.T, storage StorageAPI) {
 }

 func testStorageAPIReadAll(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	err := storage.MakeVol("foo")
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
@ -314,12 +269,6 @@ func testStorageAPIReadAll(t *testing.T, storage StorageAPI) {
 }

 func testStorageAPIReadFile(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	err := storage.MakeVol("foo")
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
@ -361,12 +310,6 @@ func testStorageAPIReadFile(t *testing.T, storage StorageAPI) {
 }

 func testStorageAPIAppendFile(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	err := storage.MakeVol("foo")
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
@ -395,12 +338,6 @@ func testStorageAPIAppendFile(t *testing.T, storage StorageAPI) {
 }

 func testStorageAPIDeleteFile(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	err := storage.MakeVol("foo")
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
@ -434,12 +371,6 @@ func testStorageAPIDeleteFile(t *testing.T, storage StorageAPI) {
 }

 func testStorageAPIRenameFile(t *testing.T, storage StorageAPI) {
-	tmpGlobalServerConfig := globalServerConfig
-	defer func() {
-		globalServerConfig = tmpGlobalServerConfig
-	}()
-	globalServerConfig = newServerConfig()
-
 	err := storage.MakeVol("foo")
 	if err != nil {
 		t.Fatalf("unexpected error %v", err)
@ -518,9 +449,11 @@ func newStorageRESTHTTPServerClient(t *testing.T) (*httptest.Server, *storageRES
 		Endpoints: Endpoints{endpoint},
 	}})

-	restClient := newStorageRESTClient(endpoint)
 	prevGlobalServerConfig := globalServerConfig
 	globalServerConfig = newServerConfig()
+	lookupConfigs(globalServerConfig)
+
+	restClient := newStorageRESTClient(endpoint)

 	return httpServer, restClient, prevGlobalServerConfig, endpointPath
 }
--- a/cmd/xl-storage-disk-id-check.go
+++ b/cmd/xl-storage-disk-id-check.go
@ -48,8 +48,8 @@ func (p *xlStorageDiskIDCheck) Hostname() string {
 }

 func (p *xlStorageDiskIDCheck) CrawlAndGetDataUsage(ctx context.Context, cache dataUsageCache) (dataUsageCache, error) {
-	if p.isDiskStale() {
-		return dataUsageCache{}, errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return dataUsageCache{}, err
 	}
 	return p.storage.CrawlAndGetDataUsage(ctx, cache)
 }
@ -66,157 +66,178 @@ func (p *xlStorageDiskIDCheck) SetDiskID(id string) {
 	p.diskID = id
 }

-func (p *xlStorageDiskIDCheck) isDiskStale() bool {
+func (p *xlStorageDiskIDCheck) checkDiskStale() error {
 	if p.diskID == "" {
-		// For empty disk-id we allow the call as the server might be coming up and trying to read format.json
-		// or create format.json
-		return false
+		// For empty disk-id we allow the call as the server might be
+		// coming up and trying to read format.json or create format.json
+		return nil
 	}
 	storedDiskID, err := p.storage.GetDiskID()
-	if err == nil && p.diskID == storedDiskID {
-		return false
+	if err != nil {
+		// return any error generated while reading `format.json`
+		return err
 	}
-	return true
+	if err == nil && p.diskID == storedDiskID {
+		return nil
+	}
+	// not the same disk we remember, take it offline.
+	return errDiskNotFound
 }

 func (p *xlStorageDiskIDCheck) DiskInfo() (info DiskInfo, err error) {
-	if p.isDiskStale() {
+	info, err = p.storage.DiskInfo()
+	if err != nil {
+		return info, err
+	}
+	if p.diskID != info.ID {
 		return info, errDiskNotFound
 	}
-	return p.storage.DiskInfo()
+	return info, nil
 }

 func (p *xlStorageDiskIDCheck) MakeVolBulk(volumes ...string) (err error) {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return err
 	}
 	return p.storage.MakeVolBulk(volumes...)
 }

 func (p *xlStorageDiskIDCheck) MakeVol(volume string) (err error) {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return err
 	}
 	return p.storage.MakeVol(volume)
 }

 func (p *xlStorageDiskIDCheck) ListVols() ([]VolInfo, error) {
-	if p.isDiskStale() {
-		return nil, errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return nil, err
 	}
 	return p.storage.ListVols()
 }

 func (p *xlStorageDiskIDCheck) StatVol(volume string) (vol VolInfo, err error) {
-	if p.isDiskStale() {
-		return vol, errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return vol, err
 	}
 	return p.storage.StatVol(volume)
 }

 func (p *xlStorageDiskIDCheck) DeleteVol(volume string, forceDelete bool) (err error) {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return err
 	}
 	return p.storage.DeleteVol(volume, forceDelete)
 }

 func (p *xlStorageDiskIDCheck) WalkVersions(volume, dirPath string, marker string, recursive bool, endWalkCh <-chan struct{}) (chan FileInfoVersions, error) {
-	if p.isDiskStale() {
-		return nil, errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return nil, err
 	}
 	return p.storage.WalkVersions(volume, dirPath, marker, recursive, endWalkCh)
 }

 func (p *xlStorageDiskIDCheck) Walk(volume, dirPath string, marker string, recursive bool, endWalkCh <-chan struct{}) (chan FileInfo, error) {
-	if p.isDiskStale() {
-		return nil, errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return nil, err
 	}
+
 	return p.storage.Walk(volume, dirPath, marker, recursive, endWalkCh)
 }

 func (p *xlStorageDiskIDCheck) WalkSplunk(volume, dirPath string, marker string, endWalkCh <-chan struct{}) (chan FileInfo, error) {
-	if p.isDiskStale() {
-		return nil, errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return nil, err
 	}
+
 	return p.storage.WalkSplunk(volume, dirPath, marker, endWalkCh)
 }

 func (p *xlStorageDiskIDCheck) ListDir(volume, dirPath string, count int) ([]string, error) {
-	if p.isDiskStale() {
-		return nil, errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return nil, err
 	}
+
 	return p.storage.ListDir(volume, dirPath, count)
 }

 func (p *xlStorageDiskIDCheck) ReadFile(volume string, path string, offset int64, buf []byte, verifier *BitrotVerifier) (n int64, err error) {
-	if p.isDiskStale() {
-		return 0, errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return 0, err
 	}
+
 	return p.storage.ReadFile(volume, path, offset, buf, verifier)
 }

 func (p *xlStorageDiskIDCheck) AppendFile(volume string, path string, buf []byte) (err error) {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.AppendFile(volume, path, buf)
 }

 func (p *xlStorageDiskIDCheck) CreateFile(volume, path string, size int64, reader io.Reader) error {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.CreateFile(volume, path, size, reader)
 }

 func (p *xlStorageDiskIDCheck) ReadFileStream(volume, path string, offset, length int64) (io.ReadCloser, error) {
-	if p.isDiskStale() {
-		return nil, errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return nil, err
 	}
+
 	return p.storage.ReadFileStream(volume, path, offset, length)
 }

 func (p *xlStorageDiskIDCheck) RenameFile(srcVolume, srcPath, dstVolume, dstPath string) error {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.RenameFile(srcVolume, srcPath, dstVolume, dstPath)
 }

 func (p *xlStorageDiskIDCheck) RenameData(srcVolume, srcPath, dataDir, dstVolume, dstPath string) error {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.RenameData(srcVolume, srcPath, dataDir, dstVolume, dstPath)
 }

 func (p *xlStorageDiskIDCheck) CheckParts(volume string, path string, fi FileInfo) (err error) {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.CheckParts(volume, path, fi)
 }

 func (p *xlStorageDiskIDCheck) CheckFile(volume string, path string) (err error) {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.CheckFile(volume, path)
 }

 func (p *xlStorageDiskIDCheck) DeleteFile(volume string, path string) (err error) {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.DeleteFile(volume, path)
 }

 func (p *xlStorageDiskIDCheck) DeleteVersions(volume string, versions []FileInfo) (errs []error) {
-	if p.isDiskStale() {
+	if err := p.checkDiskStale(); err != nil {
 		errs = make([]error, len(versions))
 		for i := range errs {
-			errs[i] = errDiskNotFound
+			errs[i] = err
 		}
 		return errs
 	}
@ -224,43 +245,49 @@ func (p *xlStorageDiskIDCheck) DeleteVersions(volume string, versions []FileInfo
 }

 func (p *xlStorageDiskIDCheck) VerifyFile(volume, path string, fi FileInfo) error {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err := p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.VerifyFile(volume, path, fi)
 }

 func (p *xlStorageDiskIDCheck) WriteAll(volume string, path string, reader io.Reader) (err error) {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.WriteAll(volume, path, reader)
 }

 func (p *xlStorageDiskIDCheck) DeleteVersion(volume, path string, fi FileInfo) (err error) {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.DeleteVersion(volume, path, fi)
 }

 func (p *xlStorageDiskIDCheck) WriteMetadata(volume, path string, fi FileInfo) (err error) {
-	if p.isDiskStale() {
-		return errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return err
 	}
+
 	return p.storage.WriteMetadata(volume, path, fi)
 }

 func (p *xlStorageDiskIDCheck) ReadVersion(volume, path, versionID string) (fi FileInfo, err error) {
-	if p.isDiskStale() {
-		return fi, errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return fi, err
 	}
+
 	return p.storage.ReadVersion(volume, path, versionID)
 }

 func (p *xlStorageDiskIDCheck) ReadAll(volume string, path string) (buf []byte, err error) {
-	if p.isDiskStale() {
-		return nil, errDiskNotFound
+	if err = p.checkDiskStale(); err != nil {
+		return nil, err
 	}
+
 	return p.storage.ReadAll(volume, path)
 }
--- a/cmd/xl-storage.go
+++ b/cmd/xl-storage.go
@ -86,9 +86,6 @@ func isValidVolname(volname string) bool {

 // xlStorage - implements StorageAPI interface.
 type xlStorage struct {
-	// Disk usage metrics
-	totalUsed uint64 // ref: https://golang.org/pkg/sync/atomic/#pkg-note-BUG
-
 	maxActiveIOCount int32
 	activeIOCount    int32

@ -408,7 +405,10 @@ func (s *xlStorage) CrawlAndGetDataUsage(ctx context.Context, cache dataUsageCac

 		var totalSize int64
 		for _, version := range fivs.Versions {
-			size := item.applyActions(ctx, objAPI, actionMeta{numVersions: len(fivs.Versions), oi: version.ToObjectInfo(item.bucket, item.objectPath())})
+			size := item.applyActions(ctx, objAPI, actionMeta{
+				numVersions: len(fivs.Versions),
+				oi:          version.ToObjectInfo(item.bucket, item.objectPath()),
+			})
 			if !version.Deleted {
 				totalSize += size
 			}
@ -422,12 +422,6 @@ func (s *xlStorage) CrawlAndGetDataUsage(ctx context.Context, cache dataUsageCac
 	}

 	dataUsageInfo.Info.LastUpdate = time.Now()
-	total := dataUsageInfo.sizeRecursive(dataUsageInfo.Info.Name)
-	if total == nil {
-		total = &dataUsageEntry{}
-	}
-	atomic.StoreUint64(&s.totalUsed, uint64(total.Size))
-
 	return dataUsageInfo, nil
 }

@ -438,8 +432,10 @@ type DiskInfo struct {
 	Free      uint64
 	Used      uint64
 	RootDisk  bool
+	Endpoint  string
 	MountPath string
-	Error     string // reports any error returned by underlying disk
+	ID        string
+	Error     string // carries the error over the network
 }

 // DiskInfo provides current information about disk space usage,
@ -455,23 +451,22 @@ func (s *xlStorage) DiskInfo() (info DiskInfo, err error) {
 		return info, err
 	}

-	used := di.Total - di.Free
-	if !s.diskMount {
-		used = atomic.LoadUint64(&s.totalUsed)
-	}
-
 	rootDisk, err := disk.IsRootDisk(s.diskPath)
 	if err != nil {
 		return info, err
 	}

-	return DiskInfo{
+	info = DiskInfo{
 		Total:     di.Total,
 		Free:      di.Free,
-		Used:      used,
+		Used:      di.Total - di.Free,
 		RootDisk:  rootDisk,
 		MountPath: s.diskPath,
-	}, nil
+	}
+
+	diskID, err := s.GetDiskID()
+	info.ID = diskID
+	return info, err
 }

 // getVolDir - will convert incoming volume names to
@ -512,7 +507,17 @@ func (s *xlStorage) GetDiskID() (string, error) {
 	if err != nil {
 		// If the disk is still not initialized.
 		if os.IsNotExist(err) {
-			return "", errUnformattedDisk
+			_, err = os.Stat(s.diskPath)
+			if err == nil {
+				// Disk is present by missing `format.json`
+				return "", errUnformattedDisk
+			}
+			if os.IsNotExist(err) {
+				return "", errDiskNotFound
+			} else if os.IsPermission(err) {
+				return "", errDiskAccessDenied
+			}
+			return "", err
 		}
 		return "", errCorruptedFormat
 	}
--- a/pkg/madmin/heal-commands.go
+++ b/pkg/madmin/heal-commands.go
@ -1,5 +1,5 @@
 /*
- * MinIO Cloud Storage, (C) 2017, 2018 MinIO, Inc.
+ * MinIO Cloud Storage, (C) 2017-2020 MinIO, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@ -99,6 +99,9 @@ const (
 	DriveStateOffline            = "offline"
 	DriveStateCorrupt            = "corrupt"
 	DriveStateMissing            = "missing"
+	DriveStatePermission         = "permission-denied"
+	DriveStateFaulty             = "faulty"
+	DriveStateUnknown            = "unknown"
 	DriveStateUnformatted        = "unformatted" // only returned by disk
 )

--- a/pkg/madmin/info-commands.go
+++ b/pkg/madmin/info-commands.go
@ -39,19 +39,9 @@ const (
 	// Add your own backend.
 )

-// DriveInfo - represents each drive info, describing
-// status, uuid and endpoint.
-type DriveInfo HealDriveInfo
-
 // StorageInfo - represents total capacity of underlying storage.
 type StorageInfo struct {
-	Used []uint64 // Used total used per disk.
-
-	Total []uint64 // Total disk space per disk.
-
-	Available []uint64 // Total disk space available per disk.
-
-	MountPaths []string // Disk mountpoints
+	Disks []Disk

 	// Backend type.
 	Backend struct {
@ -65,9 +55,6 @@ type StorageInfo struct {
 		StandardSCParity int          // Parity disks for currently configured Standard storage class.
 		RRSCData         int          // Data disks for currently configured Reduced Redundancy storage class.
 		RRSCParity       int          // Parity disks for currently configured Reduced Redundancy storage class.
-
-		// List of all disk status, this is only meaningful if BackendType is Erasure.
-		Sets [][]DriveInfo
 	}
 }

@ -282,12 +269,14 @@ type ServerProperties struct {

 // Disk holds Disk information
 type Disk struct {
+	Endpoint        string  `json:"endpoint,omitempty"`
 	DrivePath       string  `json:"path,omitempty"`
 	State           string  `json:"state,omitempty"`
 	UUID            string  `json:"uuid,omitempty"`
 	Model           string  `json:"model,omitempty"`
 	TotalSpace      uint64  `json:"totalspace,omitempty"`
 	UsedSpace       uint64  `json:"usedspace,omitempty"`
+	AvailableSpace  uint64  `json:"availspace,omitempty"`
 	ReadThroughput  float64 `json:"readthroughput,omitempty"`
 	WriteThroughPut float64 `json:"writethroughput,omitempty"`
 	ReadLatency     float64 `json:"readlatency,omitempty"`