@@ -60,7 +60,7 @@ type DeviceSet struct {

 	devicePrefix     string

 	TransactionId    uint64

 	NewTransactionId uint64

-	nextFreeDevice   int

+	nextDeviceId     int

 }

 type DiskUsage struct {

@@ -156,13 +156,6 @@ func (devices *DeviceSet) ensureImage(name string, size int64) (string, error) {

 	return filename, nil

 }

-func (devices *DeviceSet) allocateDeviceId() int {

-	// TODO: Add smarter reuse of deleted devices

-	id := devices.nextFreeDevice

-	devices.nextFreeDevice = devices.nextFreeDevice + 1

-	return id

-}

-

 func (devices *DeviceSet) allocateTransactionId() uint64 {

 	devices.NewTransactionId = devices.NewTransactionId + 1

 	return devices.NewTransactionId

@@ -299,10 +292,6 @@ func (devices *DeviceSet) loadMetaData() error {

 		d.Hash = hash

 		d.devices = devices

-		if d.DeviceId >= devices.nextFreeDevice {

-			devices.nextFreeDevice = d.DeviceId + 1

-		}

-

 		// If the transaction id is larger than the actual one we lost the device due to some crash

 		if d.TransactionId > devices.TransactionId {

 			utils.Debugf("Removing lost device %s with id %d", hash, d.TransactionId)

@@ -328,14 +317,17 @@ func (devices *DeviceSet) setupBaseImage() error {

 	utils.Debugf("Initializing base device-manager snapshot")

-	id := devices.allocateDeviceId()

+	id := devices.nextDeviceId

 	// Create initial device

-	if err := createDevice(devices.getPoolDevName(), id); err != nil {

+	if err := createDevice(devices.getPoolDevName(), &id); err != nil {

 		utils.Debugf("\n--->Err: %s\n", err)

 		return err

 	}

+	// Ids are 24bit, so wrap around

+	devices.nextDeviceId = (id + 1) & 0xffffff

+

 	utils.Debugf("Registering base device (id %v) with FS size %v", id, DefaultBaseFsSize)

 	info, err := devices.registerDevice(id, "", DefaultBaseFsSize)

 	if err != nil {

@@ -580,13 +572,16 @@ func (devices *DeviceSet) AddDevice(hash, baseHash string) error {

 		return fmt.Errorf("device %s already exists", hash)

 	}

-	deviceId := devices.allocateDeviceId()

+	deviceId := devices.nextDeviceId

-	if err := createSnapDevice(devices.getPoolDevName(), deviceId, baseInfo.Name(), baseInfo.DeviceId); err != nil {

+	if err := createSnapDevice(devices.getPoolDevName(), &deviceId, baseInfo.Name(), baseInfo.DeviceId); err != nil {

 		utils.Debugf("Error creating snap device: %s\n", err)

 		return err

 	}

+	// Ids are 24bit, so wrap around

+	devices.nextDeviceId = (deviceId + 1) & 0xffffff

+

 	if _, err := devices.registerDevice(deviceId, hash, baseInfo.Size); err != nil {

 		deleteDevice(devices.getPoolDevName(), deviceId)

 		utils.Debugf("Error registering device: %s\n", err)

@@ -64,7 +64,8 @@ var (

 	ErrLoopbackSetCapacity    = errors.New("Unable set loopback capacity")

 	ErrBusy                   = errors.New("Device is Busy")

-	dmSawBusy bool

+	dmSawBusy  bool

+	dmSawExist bool

 )

 type (

@@ -467,23 +468,33 @@ func resumeDevice(name string) error {

 	return nil

 }

-func createDevice(poolName string, deviceId int) error {

-	utils.Debugf("[devmapper] createDevice(poolName=%v, deviceId=%v)", poolName, deviceId)

-	task, err := createTask(DeviceTargetMsg, poolName)

-	if task == nil {

-		return err

-	}

+func createDevice(poolName string, deviceId *int) error {

+	utils.Debugf("[devmapper] createDevice(poolName=%v, deviceId=%v)", poolName, *deviceId)

-	if err := task.SetSector(0); err != nil {

-		return fmt.Errorf("Can't set sector")

-	}

+	for {

+		task, err := createTask(DeviceTargetMsg, poolName)

+		if task == nil {

+			return err

+		}

-	if err := task.SetMessage(fmt.Sprintf("create_thin %d", deviceId)); err != nil {

-		return fmt.Errorf("Can't set message")

-	}

+		if err := task.SetSector(0); err != nil {

+			return fmt.Errorf("Can't set sector")

+		}

-	if err := task.Run(); err != nil {

-		return fmt.Errorf("Error running createDevice")

+		if err := task.SetMessage(fmt.Sprintf("create_thin %d", *deviceId)); err != nil {

+			return fmt.Errorf("Can't set message")

+		}

+

+		dmSawExist = false

+		if err := task.Run(); err != nil {

+			if dmSawExist {

+				// Already exists, try next id

+				*deviceId++

+				continue

+			}

+			return fmt.Errorf("Error running createDevice")

+		}

+		break

 	}

 	return nil

 }

@@ -553,7 +564,7 @@ func activateDevice(poolName string, name string, deviceId int, size uint64) err

 	return nil

 }

-func createSnapDevice(poolName string, deviceId int, baseName string, baseDeviceId int) error {

+func createSnapDevice(poolName string, deviceId *int, baseName string, baseDeviceId int) error {

 	devinfo, _ := getInfo(baseName)

 	doSuspend := devinfo != nil && devinfo.Exists != 0

@@ -563,33 +574,44 @@ func createSnapDevice(poolName string, deviceId int, baseName string, baseDevice

 		}

 	}

-	task, err := createTask(DeviceTargetMsg, poolName)

-	if task == nil {

-		if doSuspend {

-			resumeDevice(baseName)

+	for {

+		task, err := createTask(DeviceTargetMsg, poolName)

+		if task == nil {

+			if doSuspend {

+				resumeDevice(baseName)

+			}

+			return err

 		}

-		return err

-	}

-	if err := task.SetSector(0); err != nil {

-		if doSuspend {

-			resumeDevice(baseName)

+		if err := task.SetSector(0); err != nil {

+			if doSuspend {

+				resumeDevice(baseName)

+			}

+			return fmt.Errorf("Can't set sector")

 		}

-		return fmt.Errorf("Can't set sector")

-	}

-	if err := task.SetMessage(fmt.Sprintf("create_snap %d %d", deviceId, baseDeviceId)); err != nil {

-		if doSuspend {

-			resumeDevice(baseName)

+		if err := task.SetMessage(fmt.Sprintf("create_snap %d %d", *deviceId, baseDeviceId)); err != nil {

+			if doSuspend {

+				resumeDevice(baseName)

+			}

+			return fmt.Errorf("Can't set message")

 		}

-		return fmt.Errorf("Can't set message")

-	}

-	if err := task.Run(); err != nil {

-		if doSuspend {

-			resumeDevice(baseName)

+		dmSawExist = false

+		if err := task.Run(); err != nil {

+			if dmSawExist {

+				// Already exists, try next id

+				*deviceId++

+				continue

+			}

+

+			if doSuspend {

+				resumeDevice(baseName)

+			}

+			return fmt.Errorf("Error running DeviceCreate (createSnapDevice)")

 		}

-		return fmt.Errorf("Error running DeviceCreate (createSnapDevice)")

+

+		break

 	}

 	if doSuspend {

@@ -18,6 +18,10 @@ func DevmapperLogCallback(level C.int, file *C.char, line C.int, dm_errno_or_cla

 		if strings.Contains(msg, "busy") {

 			dmSawBusy = true

 		}

+

+		if strings.Contains(msg, "File exists") {

+			dmSawExist = true

+		}

 	}

 	if dmLogger != nil {