for index, e := range etags {
				if partsMetadata[index].IsValid() && e == etag {
					onlineDisks[index] = disks[index]
				} else {
					onlineDisks[index] = nil
				}
			}
			return onlineDisks, modTime, etag
		}
	}

	// Create a new online disks slice, which have common uuid.
	for index, t := range modTimes {

	g := errgroup.WithNErrs(len(disks))
	for index := range disks {
		index := index
		g.Go(func() error {
			di := madmin.Disk{
				Endpoint:  endpoints[index].String(),
				PoolIndex: endpoints[index].PoolIdx,
				SetIndex:  endpoints[index].SetIdx,
				DiskIndex: endpoints[index].DiskIdx,
				Local:     endpoints[index].IsLocal,
			}
			if disks[index] == OfflineDisk {

			if err != nil {
				return err
			}
			bucketMetas[index] = meta
			return nil
		}, index)
	}

	errs := g.Wait()
	for index, err := range errs {
		if err != nil {
			internalLogOnceIf(ctx, fmt.Errorf("Unable to load bucket metadata, will be retried: %w", err),
				"load-bucket-metadata-"+buckets[index], logger.WarningKind)
		}
	}

	var storageInfo madmin.StorageInfo

	storageInfos := make([]madmin.StorageInfo, len(s.sets))

	g := errgroup.WithNErrs(len(s.sets))
	for index := range s.sets {
		index := index
		g.Go(func() error {
			storageInfos[index] = s.sets[index].StorageInfo(ctx)
			return nil
		}, index)
	}

	// Wait for the go routines.
	g.Wait()

	for _, lstorageInfo := range storageInfos {

	// checksum which are different on each disks.
	for index := range partsMetadata {
		if partsMetadata[index].IsValid() {
			partsMetadata[index].Size = fi.Size
			partsMetadata[index].ModTime = fi.ModTime
			partsMetadata[index].Metadata = fi.Metadata
			partsMetadata[index].Parts = fi.Parts
			partsMetadata[index].Checksum = fi.Checksum
			partsMetadata[index].Versioned = opts.Versioned || opts.VersionSuspended
		}
	}

	g := errgroup.WithNErrs(len(storageDisks))
	var mu sync.Mutex
	for index := range storageDisks {
		index := index
		g.Go(func() error {
			if storageDisks[index] == nil {
				// we ignore disk not found errors
				return nil
			}
			volsInfo, err := storageDisks[index].ListVols(ctx)
			if err != nil {
				return err
			}
			for _, volInfo := range volsInfo {

	if ok {
		netLockCtx = context.WithValue(netLockCtx, mcontext.ContextTraceKey, tc)
	}

	for index, c := range restClnts {
		wg.Add(1)
		// broadcast lock request to all nodes
		go func(index int, isReadLock bool, c NetLocker) {
			defer wg.Done()

			g := Granted{index: index}
			if c == nil {
				log("dsync: nil locker\n")
				ch <- g
				return
			}

			var locked bool

	g := errgroup.WithNErrs(len(users))

	for index := range users {
		index := index
		g.Go(func() error {
			userName := path.Dir(users[index])
			user, err := iamOS.loadUserIdentity(ctx, userName, userType)
			if err != nil && !errors.Is(err, errNoSuchUser) {
				return fmt.Errorf("unable to load the user `%s`: %w", userName, err)
			}
			userIdentities[index] = user
			return nil
		}, index)
	}

	// Start writing `xl.meta` to all disks in parallel.
	for index := range disks {
		index := index
		g.Go(func() error {
			if disks[index] == nil {
				return errDiskNotFound
			}
			// Pick one FileInfo for a disk at index.
			fi := files[index]
			fi.Erasure.Index = index + 1
			if fi.IsValid() {
				return disks[index].WriteMetadata(ctx, origbucket, bucket, prefix, fi)
			}
			return errFileCorrupt

			if !tt.wantIdx && len(idx) > 0 {
				t.Errorf("index returned above threshold")
			}
			if tt.wantIdx {
				if idx == nil {
					t.Errorf("no index returned")
				}
				var index s2.Index
				_, err = index.Load(s2.RestoreIndexHeaders(idx))
				if err != nil {
					t.Errorf("error loading index: %v", err)
				}
				t.Log("size:", len(idx))
				t.Log(string(index.JSON()))