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)
}

	var buf Buffer
	s := ""
	for i := 0; i < 50; i++ {
		wlen := rand.Intn(len(testString))
		if i%2 == 0 {
			s = fillString(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, testString[0:wlen])
		} else {
			s = fillBytes(t, "TestMixedReadsAndWrites (1)", &buf, s, 1, testBytes[0:wlen])
		}

		rlen := rand.Intn(len(testString))
		fub := make([]byte, rlen)
		n, _ := buf.Read(fub)
		s = s[n:]
	}

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 {

}

var makeFieldsInput = func() []byte {
	x := make([]byte, 1<<20)
	// Input is ~10% space, ~10% 2-byte UTF-8, rest ASCII non-space.
	r := rand.New(rand.NewSource(99))
	for i := range x {
		switch r.Intn(10) {
		case 0:
			x[i] = ' '
		case 1:
			if i > 0 && x[i-1] == 'x' {
				copy(x[i-1:], "χ")
				break
			}
			fallthrough
		default:
			x[i] = 'x'
		}
	}
	return x

	rng := rand.New(rand.NewSource(time.Now().UTC().UnixNano()))
	var d net.Dialer
	var retry int
	for retry < len(hosts) {
		ctx, cancel := context.WithTimeout(GlobalContext, 300*time.Millisecond)

		host = hosts[rng.Intn(len(hosts))]
		conn, err := d.DialContext(ctx, "tcp", host)
		cancel()
		if err != nil {
			retry++
			continue
		}
		conn.Close()
		break
	}

	return host
}

		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
	}