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:

// 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
}