for i := 0; i <= f; i++ {
			diskErrors[i] = nil
		}
		erasureDisks := xl.getDisks()
		for i := range erasureDisks[:9] {
			switch diskType := erasureDisks[i].(type) {
			case *naughtyDisk:
				erasureDisks[i] = newNaughtyDisk(diskType.disk, diskErrors, errFaultyDisk)
			default:
				erasureDisks[i] = newNaughtyDisk(erasureDisks[i], diskErrors, errFaultyDisk)
			}
		}
		z.serverPools[0].erasureDisksMu.Lock()

				if errs[j] != nil {
					t.Fatalf("expected error to be nil: %s", errs[j])
				}
				partsMetadata[j].ModTime = test.modTimes[j]
			}

			if erasureDisks, err = writeUniqueFileInfo(ctx, erasureDisks, "", bucket, object, partsMetadata, diskCount(erasureDisks)); err != nil {
				t.Fatal(ctx, err)
			}

			tamperedIndex := -1
			switch test._tamperBackend {
			case deletePart:

	// Test 1: Remove the object backend files from the first disk.
	z := objLayer.(*erasureServerPools)
	er := z.serverPools[0].sets[0]
	erasureDisks := er.getDisks()
	firstDisk := erasureDisks[0]
	secondDisk := erasureDisks[1]

	fileInfos, errs := readAllFileInfo(ctx, erasureDisks, "", bucket, object, "", false, true)
	fi, err := getLatestFileInfo(ctx, fileInfos, er.defaultParityCount, errs)
	if err != nil {

	defer cancel()

	nDisks := 16 // Maximum disks.
	var erasureDisks []string
	for i := 0; i < nDisks; i++ {
		// Do not attempt to create this path, the test validates
		// so that newErasureSets initializes non existing paths
		// and successfully returns initialized object layer.
		disk := filepath.Join(globalTestTmpDir, "minio-"+nextSuffix())
		erasureDisks = append(erasureDisks, disk)
		defer os.RemoveAll(disk)
	}

// current design.
type erasureSets struct {
	sets []*erasureObjects

	// Reference format.
	format *formatErasureV3

	// erasureDisks mutex to lock erasureDisks.
	erasureDisksMu sync.RWMutex

	// Re-ordered list of disks per set.
	erasureDisks [][]StorageAPI

	// Distributed locker clients.
	erasureLockers setsDsyncLockers

	// Distributed lock owner (constant per running instance).

	}

	z := obj.(*erasureServerPools)
	er := z.serverPools[0].sets[0]

	erasureDisks := er.getDisks()
	ridx := rand.Intn(len(erasureDisks))

	z.serverPools[0].erasureDisksMu.Lock()
	er.getDisks = func() []StorageAPI {
		erasureDisks[ridx] = newNaughtyDisk(erasureDisks[ridx], nil, errFaultyDisk)
		return erasureDisks
	}
	z.serverPools[0].erasureDisksMu.Unlock()

func getRandomDisks(n int) ([]string, error) {
	var erasureDisks []string
	for i := 0; i < n; i++ {
		path, err := os.MkdirTemp(globalTestTmpDir, "minio-")
		if err != nil {
			// Remove directories created so far.
			removeRoots(erasureDisks)
			return nil, err
		}
		erasureDisks = append(erasureDisks, path)
	}
	return erasureDisks, nil
}

	// Now check if we actually wrote to backend (regardless of the response
	// returned by the server).
	z := obj.(*erasureServerPools)
	xl := z.serverPools[0].sets[0]
	erasureDisks := xl.getDisks()
	parts, errs := readAllFileInfo(ctx, erasureDisks, "", bucketName, objectName, "", false, false)
	for i := range parts {
		if errs[i] == nil {
			if parts[i].Name == objectName {

	// Now check if we actually wrote to backend (regardless of the response
	// returned by the server).
	z := obj.(*erasureServerPools)
	xl := z.serverPools[0].sets[0]
	erasureDisks := xl.getDisks()
	parts, errs := readAllFileInfo(ctx, erasureDisks, "", bucketName, objectName+"/upload.txt", "", false, false)
	for i := range parts {
		if errs[i] == nil {
			if parts[i].Name == objectName+"/upload.txt" {