if err != nil {
						b.Fatal(err)
					}
					// Update modtime for resorting...
					fi.ModTime = fi.ModTime.Add(-time.Second)
					// Update a random version.
					fi.VersionID = ids[rng.Intn(size)]
					// Update...
					err = xl.UpdateObjectVersion(fi)
					if err != nil {
						b.Fatal(err)
					}
					// Save...
					dump, err = xl.AppendTo(dump[:0])
					if err != nil {

					}

					// Expire 50%
					expired := time.Now().Add(-time.Hour * 2)
					for _, v := range l.lockMap {
						for i := range v {
							if rng.Intn(2) == 0 {
								v[i].TimeLastRefresh = expired.UnixNano()
							}
						}
					}
					start = time.Now()
					l.expireOldLocks(time.Hour)

	const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
	// seeding the random number generator.
	rand.Seed(UTCNow().UnixNano())
	// pick a character randomly.
	return []byte{letterBytes[rand.Intn(len(letterBytes))]}
}

// picks a random byte and repeats it to size bytes.
func generateBytesData(size int) []byte {
	// repeat the random character chosen size
	return bytes.Repeat(getRandomByte(), size)
}

func getRandomRange(minN, maxN int, seed int64) int {
	// special value -1 means no explicit seeding.
	if seed == -1 {
		return rand.New(rand.NewSource(time.Now().UnixNano())).Intn(maxN-minN) + minN
	}
	return rand.New(rand.NewSource(seed)).Intn(maxN-minN) + minN
}

// Randomizes the order of bytes in the byte array
// using Knuth Fisher-Yates shuffle algorithm.
func randomizeBytes(s []byte, seed int64) []byte {

		t.Fatalf("%s : %s", instanceType, err.Error())
	}

	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
	}