diff --git a/headers/private/storage/DiskDevice.h b/headers/private/storage/DiskDevice.h
index b1394418bc..92c0cf3f8d 100644
--- a/headers/private/storage/DiskDevice.h
+++ b/headers/private/storage/DiskDevice.h
@@ -40,9 +40,17 @@ private:
 	friend class BDiskDeviceList;
 	friend class BDiskDeviceRoster;
 
+	BDiskDevice::BDiskDevice(const BDiskDevice &);
+	BDiskDevice &BDiskDevice::operator=(const BDiskDevice &);
+
+	static status_t _GetData(partition_id id, bool deviceOnly, bool shadow,
+							 size_t neededSize, user_disk_device_data **data);
+
 	status_t _SetTo(partition_id id, bool deviceOnly, bool shadow,
 					size_t neededSize);
 	status_t _SetTo(user_disk_device_data *data);
+	status_t _Update(bool shadow, bool *updated);
+	status_t _Update(user_disk_device_data *data, bool *updated);
 
 	virtual bool _AcceptVisitor(BDiskDeviceVisitor *visitor, int32 level);
 
diff --git a/headers/private/storage/Partition.h b/headers/private/storage/Partition.h
index a36da525fb..5c55d06fb9 100644
--- a/headers/private/storage/Partition.h
+++ b/headers/private/storage/Partition.h
@@ -139,10 +139,15 @@ private:
 	status_t _SetTo(BDiskDevice *device, BPartition *parent,
 					user_partition_data *data);
 	void _Unset();
+	status_t _RemoveObsoleteDescendants(user_partition_data *data,
+										bool *updated);
+	status_t _Update(user_partition_data *data, bool *updated);
+	void _RemoveChild(int32 index);
 
 	bool _IsShadow() const;
 	partition_id _ShadowID() const;
 	disk_system_id _DiskSystem() const;
+	int32 _ChangeCounter() const;
 
 	int32 _CountDescendants() const;
 	int32 _Level() const;
diff --git a/src/kits/storage/DiskDevice.cpp b/src/kits/storage/DiskDevice.cpp
index 8cd31d7e2e..c8c93689bf 100644
--- a/src/kits/storage/DiskDevice.cpp
+++ b/src/kits/storage/DiskDevice.cpp
@@ -140,51 +140,7 @@ BDiskDevice::SetTo(partition_id id)
 status_t
 BDiskDevice::Update(bool *updated)
 {
-/*
-	// get a messenger for the disk device manager
-// TODO: Cache the messenger? Maybe add a global variable?
-	BMessenger manager;
-	status_t error = get_disk_device_messenger(&manager);
-	// compose request message
-	BMessage request(B_REG_UPDATE_DISK_DEVICE);
-	if (error == B_OK)
-		error = request.AddInt32("device_id", fUniqueID);
-	if (error == B_OK)
-		error = request.AddInt32("change_counter", fChangeCounter);
-	if (error == B_OK)
-		error = request.AddInt32("update_policy", B_REG_DEVICE_UPDATE_CHANGED);
-	// send request
-	BMessage reply;
-	if (error == B_OK)
-		error = manager.SendMessage(&request, &reply);
-	// analyze reply
-	bool upToDate = true;
-	if (error == B_OK) {
-		// result
-		status_t result = B_OK;
-		error = reply.FindInt32("result", &result);
-		if (error == B_OK)
-			error = result;
-		if (error == B_OK)
-			error = reply.FindBool("up_to_date", &upToDate);
-	}
-	// get the archived device, if not up to date
-	if (error == B_OK && !upToDate) {
-		BMessage archive;
-		error = reply.FindMessage("device", &archive);
-		if (error == B_OK)
-			error = _Update(&archive);
-	}
-	// set result / cleanup on error
-	if (error == B_OK) {
-		if (updated)
-			*updated = !upToDate;
-	} else
-		Unset();
-	return error;
-*/
-	// not implemented
-	return B_ERROR;
+	return _Update(_IsShadow(), updated);
 }
 
 // Unset
@@ -235,8 +191,12 @@ BDiskDevice::PrepareModifications()
 	if (error != B_OK)
 		return error;
 	// update
-	// TODO: Add an _Update(bool shadow)?
-	return _SetTo(ID(), true, true, 0);
+	error = _Update(true, NULL);
+	if (error != B_OK) {
+		// bad -- cancelling the modifications is all we can do
+		_kern_cancel_disk_device_modifications(ID());
+	}
+	return error;
 }
 
 // CommitModifications
@@ -264,12 +224,27 @@ BDiskDevice::CancelModifications()
 	return error;
 }
 
-// _SetTo
-status_t
-BDiskDevice::_SetTo(partition_id id, bool deviceOnly, bool shadow,
-					size_t neededSize)
+// copy constructor
+/*!	\brief Privatized copy constructor to avoid usage.
+*/
+BDiskDevice::BDiskDevice(const BDiskDevice &)
+{
+}
+
+// =
+/*!	\brief Privatized assignment operator to avoid usage.
+*/
+BDiskDevice &
+BDiskDevice::operator=(const BDiskDevice &)
+{
+	return *this;
+}
+
+// _GetData
+status_t
+BDiskDevice::_GetData(partition_id id, bool deviceOnly, bool shadow,
+					  size_t neededSize, user_disk_device_data **data)
 {
-	Unset();
 	// get the device data
 	void *buffer = NULL;
 	size_t bufferSize = 0;
@@ -296,12 +271,29 @@ BDiskDevice::_SetTo(partition_id id, bool deviceOnly, bool shadow,
 				error = B_NO_MEMORY;
 		}
 	} while (error == B_BUFFER_OVERFLOW);
+	// set result / cleanup on error
+	if (error == B_OK)
+		*data = (user_disk_device_data*)buffer;
+	else if (buffer)
+		free(buffer);
+	return error;
+}
+
+// _SetTo
+status_t
+BDiskDevice::_SetTo(partition_id id, bool deviceOnly, bool shadow,
+					size_t neededSize)
+{
+	Unset();
+	// get the device data
+	user_disk_device_data *data = NULL;
+	status_t error = _GetData(id, deviceOnly, shadow, neededSize, &data);
 	// set the data
 	if (error == B_OK)
-		error = _SetTo((user_disk_device_data*)buffer);
+		error = _SetTo(data);
 	// cleanup on error
-	if (error != B_OK)
-		free(buffer);
+	if (error != B_OK && data)
+		free(data);
 	return error;
 }
 
@@ -324,6 +316,54 @@ BDiskDevice::_SetTo(user_disk_device_data *data)
 	return error;
 }
 
+// _Update
+status_t
+BDiskDevice::_Update(bool shadow, bool *updated)
+{
+	if (InitCheck() != B_OK)
+		return InitCheck();
+	// get the device data
+	user_disk_device_data *data = NULL;
+	status_t error = _GetData(ID(), true, shadow, 0, &data);
+	// set the data
+	if (error == B_OK)
+		error = _Update(data, updated);
+	// cleanup on error
+	if (error != B_OK && data)
+		free(data);
+	return error;
+}
+
+// _Update
+status_t
+BDiskDevice::_Update(user_disk_device_data *data, bool *updated)
+{
+	if (!data || !fDeviceData || ID() != data->device_partition_data.id)
+		return B_BAD_VALUE;
+	bool _updated;
+	if (!updated)
+		updated = &_updated;
+	*updated = false;
+	// remove obsolete partitions
+	status_t error = _RemoveObsoleteDescendants(&data->device_partition_data,
+												updated);
+	if (error != B_OK)
+		return error;
+	// update existing partitions and add new ones
+	error = BPartition::_Update(&data->device_partition_data, updated);
+	if (error == B_OK) {
+		user_disk_device_data *oldData = fDeviceData;
+		fDeviceData = data;
+		// check for changes
+		if (data->device_flags != oldData->device_flags
+			|| strcmp(data->path, oldData->path)) {
+			*updated = true;
+		}
+		free(oldData);
+	}
+	return error;
+}
+
 // _AcceptVisitor
 bool
 BDiskDevice::_AcceptVisitor(BDiskDeviceVisitor *visitor, int32 level)
@@ -331,518 +371,3 @@ BDiskDevice::_AcceptVisitor(BDiskDeviceVisitor *visitor, int32 level)
 	return visitor->Visit(this);
 }
 
-
-#if 0
-
-// Path
-/*!	\brief Returns the path to the device.
-	\return The path to the device.
-*/
-const char *
-BDiskDevice::Path() const
-{
-	return (fPath[0] != '\0' ? fPath : NULL);
-}
-
-// skip_string_component
-static
-const char *
-skip_string_component(const char *str, const char *component)
-{
-	const char *remainder = NULL;
-	if (str && component) {
-		size_t len = strlen(component);
-		if (!strncmp(str, component, len))
-			remainder = str + len;
-	}
-	return remainder;
-}
-
-// GetName
-/*!	\brief Returns a human readable name for the device.
-
-	The method tries to interpret the device path, which it can do only for
-	floppy, IDE and SCSI devices, for others the device path is returned.
-
-	\param name Pointer to a pre-allocated BString to be set to the device
-		   name.
-	\param includeBusID \c true, if the bus ID shall be included in the name
-		   to be returned (of interest for SCSI devices).
-	\param includeLUN \c true, if the LUN shall be included in the name
-		   to be returned (of interest for SCSI devices).
-	\return
-	- \c B_OK: Everything went fine.
-	- \c B_BAD_VALUE: \c NULL \a name.
-	- \c B_NO_INIT: The device is not properly initialized.
-*/
-status_t
-BDiskDevice::GetName(BString *name, bool includeBusID, bool includeLUN) const
-{
-	// check params and initialization
-	status_t error = (name ? B_OK : B_BAD_VALUE);
-	const char *path = Path();
-	if (error == B_OK && !path)
-		error = B_BAD_VALUE;
-	// analyze the device path
-	if (error == B_OK) {
-		bool recognized = false;
-		const char *prefix = "/dev/disk/";
-		size_t prefixLen = strlen(prefix);
-		if (!strncmp(path, prefix, prefixLen)) {
-			path = path + prefixLen;
-			// check first component
-			const char *tail = NULL;
-			// floppy
-			if (skip_string_component(path, "floppy/")) {
-				name->SetTo("floppy");
-				recognized = true;
-			// ide
-			} else if ((tail = skip_string_component(path, "ide/"))) {
-				int controller = 0;
-				bool master = false;
-				const char *_tail = tail;
-				if ((((tail = skip_string_component(_tail, "atapi/")))
-					 || ((tail = skip_string_component(_tail, "ata/"))))
-					&& isdigit(*tail)) {
-					controller = atoi(tail);
-					master = false;
-					if ((tail = strchr(tail, '/'))) {
-						tail++;
-						if (skip_string_component(tail, "master/")) {
-							master = true;
-							recognized = true;
-						} else if (skip_string_component(tail, "slave/"))
-							recognized = true;
-					}
-				}
-				if (recognized) {
-					name->SetTo("IDE ");
-					*name << (master ? "master" : "slave") << " bus:"
-						<< controller;
-				}
-			// scsi
-			} else if ((tail = skip_string_component(path, "scsi/"))) {
-				int bus = 0;
-				int id = 0;
-				int lun = 0;
-				if (sscanf(tail, "%d/%d/%d/raw", &bus, &id, &lun) == 3) {
-					recognized = true;
-					name->SetTo("SCSI");
-					if (includeBusID)
-						*name << " bus:" << bus;
-					*name << " id:" << id;
-					if (includeLUN)
-						*name << " lun:" << lun;
-				}
-			}
-		}
-		if (!recognized)
-			name->SetTo(path);
-	}
-	return error;
-}
-
-// GetName
-/*!	\brief Returns a human readable name for the device.
-
-	The method tries to interpret the device path, which it can do only for
-	floppy, IDE and SCSI devices, for others the device path is returned.
-
-	\param name Pointer to a pre-allocated char buffer into which the device
-		   name shall be copied.
-	\param includeBusID \c true, if the bus ID shall be included in the name
-		   to be returned (of interest for SCSI devices).
-	\param includeLUN \c true, if the LUN shall be included in the name
-		   to be returned (of interest for SCSI devices).
-	- \c B_OK: Everything went fine.
-	- \c B_BAD_VALUE: \c NULL \a name.
-	- \c B_NO_INIT: The device is not properly initialized.
-*/
-status_t
-BDiskDevice::GetName(char *name, bool includeBusID, bool includeLUN) const
-{
-	status_t error = (name ? B_OK : B_BAD_VALUE);
-	if (error == B_OK) {
-		BString _name;
-		error = GetName(&_name, includeBusID, includeLUN);
-		if (error == B_OK)
-			strcpy(name, _name.String());
-	}
-	return error;
-}
-
-// IsReadOnly
-/*!	\brief Returns whether the device is read-only.
-	\return \c true, if the device is read-only, \c false otherwise.
-*/
-bool
-BDiskDevice::IsReadOnly() const
-{
-	return fReadOnly;
-}
-
-// IsFloppy
-/*!	\brief Returns whether the device is a floppy device.
-	\return \c true, if the device is a floppy device, \c false otherwise.
-*/
-bool
-BDiskDevice::IsFloppy() const
-{
-	return !strcmp(fPath, "/dev/disk/floppy/raw");
-}
-
-// Type
-/*!	\brief Returns the type of the device.
-
-	The type may be one of the following (note, that not all types make sense
-	for storage device, but they are listed anyway):
-	- \c B_DISK: Hard disks, floppy disks, etc.
-	- \c B_TAPE: Tape drives.
-	- \c B_PRINTER: Printers.
-	- \c B_CPU: CPU devices.
-	- \c B_WORM: Write-once, read-many devives.
-	- \c B_CD: CD ROMs.
-	- \c B_SCANNER: Scanners.
-	- \c B_OPTICAL: Optical devices.
-	- \c B_JUKEBOX: Jukeboxes.
-	- \c B_NETWORK: Network devices.
-	\return The type of the device.
-*/
-uint8
-BDiskDevice::Type() const
-{
-	return fType;
-}
-
-// UniqueID
-/*!	\brief Returns a unique identifier for this device.
-
-	The ID is not persistent, i.e. in general won't be the same after
-	rebooting.
-
-	\see BDiskDeviceRoster::GetDeviceWithID().
-
-	\return A unique identifier for this device.
-*/
-int32
-BDiskDevice::UniqueID() const
-{
-	return fUniqueID;
-}
-
-// LowLevelFormat
-/*!	\brief Low level formats the device.
-	\return \c B_OK, if everything went fine, another error code otherwise.
-*/
-status_t
-BDiskDevice::LowLevelFormat()
-{
-	return B_ERROR;	// not implemented
-}
-
-// VisitEachSession
-/*!	\brief Iterates through the device's sessions.
-
-	The supplied visitor's Visit(BSession*) is invoked for each session.
-	If Visit() returns \c true, the iteration is terminated and the BSession
-	object just visited is returned.
-
-	\param visitor The visitor.
-	\return The BSession object at which the iteration was terminated, or
-			\c NULL, if the iteration has not been terminated.
-*/
-BSession *
-BDiskDevice::VisitEachSession(BDiskDeviceVisitor *visitor)
-{
-	if (visitor) {
-		for (int32 i = 0; BSession *session = SessionAt(i); i++) {
-			if (visitor->Visit(session))
-				return session;
-		}
-	}
-	return NULL;
-}
-
-// VisitEachPartition
-/*!	\brief Iterates through the device's partitions.
-
-	The supplied visitor's Visit(BPartition*) is invoked for each partition.
-	If Visit() returns \c true, the iteration is terminated and the BPartition
-	object just visited is returned.
-
-	\param visitor The visitor.
-	\return The BPartition object at which the iteration was terminated, or
-			\c NULL, if the iteration has not been terminated.
-*/
-BPartition *
-BDiskDevice::VisitEachPartition(BDiskDeviceVisitor *visitor)
-{
-	if (visitor) {
-		for (int32 i = 0; BSession *session = SessionAt(i); i++) {
-			if (BPartition *partition = session->VisitEachPartition(visitor))
-				return partition;
-		}
-	}
-	return NULL;
-}
-
-// Traverse
-/*!	\brief Pre-order traverses the tree of the spanned by the BDiskDevice and
-		   its subobjects.
-
-	The supplied visitor's Visit() is invoked for the device object itself, 
-	for each session and for each partition.
-	If Visit() returns \c true, the iteration is terminated and this method
-	returns \c true as well.
-
-	\param visitor The visitor.
-	\return \c true, if the iteration was terminated, \c false otherwise.
-*/
-bool
-BDiskDevice::Traverse(BDiskDeviceVisitor *visitor)
-{
-	if (visitor) {
-		// visit the device itself
-		if (visitor->Visit(this))
-			return true;
-		for (int32 i = 0; BSession *session = SessionAt(i); i++) {
-			// visit the session
-			if (visitor->Visit(session))
-				return true;
-			// visit all partitions on the session
-			if (session->VisitEachPartition(visitor))
-				return true;
-		}
-	}
-	return false;
-}
-
-// SessionWithID
-/*!	\brief Returns the session on the device, that has a certain ID.
-	\param id The ID of the session to be returned.
-	\return The session with ID \a id, or \c NULL, if a session with that
-			ID does not exist on this device.
-*/
-BSession *
-BDiskDevice::SessionWithID(int32 id)
-{
-	IDFinderVisitor visitor(id);
-	return VisitEachSession(&visitor);
-}
-
-// PartitionWithID
-/*!	\brief Returns the partition on the device, that has a certain ID.
-	\param id The ID of the partition to be returned.
-	\return The partition with ID \a id, or \c NULL, if a partition with that
-			ID does not exist on this device.
-*/
-BPartition *
-BDiskDevice::PartitionWithID(int32 id)
-{
-	IDFinderVisitor visitor(id);
-	return VisitEachPartition(&visitor);
-}
-
-// copy constructor
-/*!	\brief Privatized copy constructor to avoid usage.
-*/
-BDiskDevice::BDiskDevice(const BDiskDevice &)
-{
-}
-
-// =
-/*!	\brief Privatized assignment operator to avoid usage.
-*/
-BDiskDevice &
-BDiskDevice::operator=(const BDiskDevice &)
-{
-	return *this;
-}
-
-// find_string
-static
-status_t
-find_string(BMessage *message, const char *name, char *buffer)
-{
-	const char *str;
-	status_t error = message->FindString(name, &str);
-	if (error == B_OK)
-		strcpy(buffer, str);
-	return error;
-}
-
-// _Unarchive
-status_t
-BDiskDevice::_Unarchive(BMessage *archive)
-{
-//printf("BDiskDevice::_Unarchive()\n");
-//archive->PrintToStream();
-	Unset();
-	status_t error = (archive ? B_OK : B_BAD_VALUE);
-	if (error == B_OK) {
-		// ID and change counter
-		if (error == B_OK)
-			error = archive->FindInt32("id", &fUniqueID);
-		if (error == B_OK)
-			error = archive->FindInt32("change_counter", &fChangeCounter);
-		// geometry
-		if (error == B_OK)
-			error = archive->FindInt64("size", &fSize);
-		if (error == B_OK)
-			error = archive->FindInt32("block_size", &fBlockSize);
-		if (error == B_OK)
-			error = archive->FindInt8("type", (int8*)&fType);
-		if (error == B_OK)
-			error = archive->FindBool("removable", &fRemovable);
-		if (error == B_OK)
-			error = archive->FindBool("read_only", &fReadOnly);
-		// other data
-		if (error == B_OK)
-			error = find_string(archive, "path", fPath);
-		if (error == B_OK)
-			error = archive->FindInt32("media_status", &fMediaStatus);
-		// sessions
-		type_code fieldType;
-		int32 count = 0;
-		if (error == B_OK) {
-			if (archive->GetInfo("sessions", &fieldType, &count) != B_OK)
-				count = 0;
-		}
-		for (int32 i = 0; error == B_OK && i < count; i++) {
-			// get the archived session
-			BMessage sessionArchive;
-			error = archive->FindMessage("sessions", i, &sessionArchive);
-			// allocate a session object
-			BSession *session = NULL;
-			if (error == B_OK) {
-				session = new(nothrow) BSession;
-				if (!session)
-					error = B_NO_MEMORY;
-			}
-			// unarchive the session
-			if (error == B_OK)
-				error = session->_Unarchive(&sessionArchive);
-			// add the session
-			if (error == B_OK && !_AddSession(session))
-				error = B_NO_MEMORY;
-			// cleanup on error
-			if (error != B_OK && session)
-				delete session;
-		}
-	}
-	// cleanup on error
-	if (error != B_OK)
-		Unset();
-//printf("BDiskDevice::_Unarchive() done: %s\n", strerror(error));
-	return error;
-}
-
-// _Update
-status_t
-BDiskDevice::_Update(BMessage *archive)
-{
-	status_t error = (archive ? B_OK : B_BAD_VALUE);
-	bool upToDate = false;
-	if (error == B_OK) {
-		// ID and change counter
-		int32 id;
-		if (error == B_OK)
-			error = archive->FindInt32("id", &id);
-		if (error == B_OK && id != fUniqueID)
-			error = B_ERROR;
-		int32 changeCounter;
-		if (error == B_OK)
-			error = archive->FindInt32("change_counter", &changeCounter);
-		upToDate = (fChangeCounter == changeCounter);
-		fChangeCounter = changeCounter;
-	}
-	if (error == B_OK && !upToDate) {
-		// geometry
-		if (error == B_OK)
-			error = archive->FindInt64("size", &fSize);
-		if (error == B_OK)
-			error = archive->FindInt32("block_size", &fBlockSize);
-		if (error == B_OK)
-			error = archive->FindInt8("type", (int8*)&fType);
-		if (error == B_OK)
-			error = archive->FindBool("removable", &fRemovable);
-		if (error == B_OK)
-			error = archive->FindBool("read_only", &fReadOnly);
-		// other data
-		if (error == B_OK)
-			error = find_string(archive, "path", fPath);
-		if (error == B_OK)
-			error = archive->FindInt32("media_status", &fMediaStatus);
-		// sessions
-		// copy old session list and empty it
-		BObjectList<BSession> sessions;
-		for (int32 i = 0; BSession *session = fSessions.ItemAt(i); i++)
-			sessions.AddItem(session);
-		for (int32 i = fSessions.CountItems() - 1; i >= 0; i--)
-			fSessions.RemoveItemAt(i);
-		// get the session count
-		type_code fieldType;
-		int32 count = 0;
-		if (error == B_OK) {
-			if (archive->GetInfo("sessions", &fieldType, &count) != B_OK)
-				count = 0;
-		}
-		for (int32 i = 0; error == B_OK && i < count; i++) {
-			// get the archived session
-			BMessage sessionArchive;
-			error = archive->FindMessage("sessions", i, &sessionArchive);
-			// check, whether we do already know that session
-			int32 sessionID;
-			if (error == B_OK)
-				error = sessionArchive.FindInt32("id", &sessionID);
-			BSession *session = NULL;
-			for (int32 k = 0; k < sessions.CountItems(); k++) {
-				BSession *oldSession = sessions.ItemAt(i);
-				if (oldSession->UniqueID() == sessionID) {
-					session = oldSession;
-					break;
-				}
-			}
-			if (error == B_OK) {
-				if (session) {
-					// the session is known: just update it
-					error = session->_Update(&sessionArchive);
-				} else {
-					// the session is unknown
-					// allocate a session object
-					session = new(nothrow) BSession;
-					if (!session)
-						error = B_NO_MEMORY;
-					// unarchive the session
-					if (error == B_OK)
-						error = session->_Unarchive(&sessionArchive);
-				}
-			}
-			// add the session
-			if (error == B_OK && !_AddSession(session))
-				error = B_NO_MEMORY;
-			// cleanup on error
-			if (error != B_OK && session)
-				delete session;
-		}
-		// delete all obsolete sessions
-		for (int32 i = sessions.CountItems() - 1; i >= 0; i--)
-			delete sessions.RemoveItemAt(i);
-	}
-	// cleanup on error
-	if (error != B_OK)
-		Unset();
-	return error;
-}
-
-// _AddSession
-bool
-BDiskDevice::_AddSession(BSession *session)
-{
-	bool result = fSessions.AddItem(session);
-	if (result)
-		session->_SetDevice(this);
-	return result;
-}
-
-#endif	//0
diff --git a/src/kits/storage/Partition.cpp b/src/kits/storage/Partition.cpp
index 687411c440..6a97a8ae2a 100644
--- a/src/kits/storage/Partition.cpp
+++ b/src/kits/storage/Partition.cpp
@@ -405,7 +405,7 @@ BPartition::GetPartitioningInfo(BPartitioningInfo *info) const
 {
 	if (!info || !fPartitionData || !_IsShadow())
 		return B_BAD_VALUE;
-	return info->_SetTo(_ShadowID());
+	return info->_SetTo(_ShadowID(), _ChangeCounter());
 }
 
 // VisitEachChild
@@ -437,6 +437,7 @@ BPartition::CanDefragment(bool *whileMounted) const
 {
 	return (fPartitionData && _IsShadow()
 			&& _kern_supports_defragmenting_partition(_ShadowID(),
+													  _ChangeCounter(),
 													  whileMounted));
 }
 
@@ -446,7 +447,7 @@ BPartition::Defragment() const
 {
 	if (!fPartitionData || !_IsShadow())
 		return B_BAD_VALUE;
-	status_t error = _kern_defragment_partition(_ShadowID());
+	status_t error = _kern_defragment_partition(_ShadowID(), _ChangeCounter());
 	if (error == B_OK)
 		error = Device()->Update();
 	return error;
@@ -457,8 +458,8 @@ bool
 BPartition::CanRepair(bool checkOnly, bool *whileMounted) const
 {
 	return (fPartitionData && _IsShadow()
-			&& _kern_supports_repairing_partition(_ShadowID(), checkOnly,
-												  whileMounted));
+			&& _kern_supports_repairing_partition(_ShadowID(), _ChangeCounter(),
+												  checkOnly, whileMounted));
 }
 
 // Repair
@@ -467,7 +468,8 @@ BPartition::Repair(bool checkOnly) const
 {
 	if (!fPartitionData || !_IsShadow())
 		return B_BAD_VALUE;
-	status_t error = _kern_repair_partition(_ShadowID(), checkOnly);
+	status_t error = _kern_repair_partition(_ShadowID(), _ChangeCounter(),
+											checkOnly);
 	if (error == B_OK)
 		error = Device()->Update();
 	return error;
@@ -478,7 +480,7 @@ bool
 BPartition::CanResize(bool *canResizeContents, bool *whileMounted) const
 {
 	return (fPartitionData && !IsDevice() && Parent() && _IsShadow()
-			&& _kern_supports_resizing_partition(_ShadowID(),
+			&& _kern_supports_resizing_partition(_ShadowID(), _ChangeCounter(),
 					canResizeContents, whileMounted));
 }
 
@@ -488,7 +490,8 @@ BPartition::ValidateResize(off_t *size, bool resizeContents) const
 {
 	if (!fPartitionData || IsDevice() || !Parent() || !_IsShadow() || !size)
 		return B_BAD_VALUE;
-	return _kern_validate_resize_partition(_ShadowID(), size, resizeContents);
+	return _kern_validate_resize_partition(_ShadowID(), _ChangeCounter(), size,
+										   resizeContents);
 }
 
 // Resize
@@ -497,7 +500,8 @@ BPartition::Resize(off_t size, bool resizeContents)
 {
 	if (!fPartitionData || IsDevice() || !Parent() || !_IsShadow())
 		return B_BAD_VALUE;
-	status_t error = _kern_resize_partition(_ShadowID(), size, resizeContents);
+	status_t error = _kern_resize_partition(_ShadowID(), _ChangeCounter(),
+											size, resizeContents);
 	if (error == B_OK)
 		error = Device()->Update();
 	return error;
@@ -534,8 +538,9 @@ BPartition::CanMove(BObjectList<BPartition> *unmovableDescendants,
 		}
 	}
 	// get the info
-	bool result = _kern_supports_moving_partition(_ShadowID(), unmovableIDs,
-						needUnmountingIDs, descendantCount);
+	bool result = _kern_supports_moving_partition(_ShadowID(),
+						_ChangeCounter(), unmovableIDs, needUnmountingIDs,
+						descendantCount);
 	if (result) {
 		// find unmovable BPartition objects for returned IDs
 		for (int32 i = 0; i < descendantCount && unmovableIDs[i] != -1; i++) {
@@ -562,7 +567,8 @@ BPartition::ValidateMove(off_t *newOffset, bool force) const
 		|| !newOffset) {
 		return B_BAD_VALUE;
 	}
-	return _kern_validate_move_partition(_ShadowID(), newOffset, force);
+	return _kern_validate_move_partition(_ShadowID(), _ChangeCounter(),
+										 newOffset, force);
 }
 
 // Move
@@ -571,7 +577,8 @@ BPartition::Move(off_t newOffset, bool force)
 {
 	if (!fPartitionData || IsDevice() || !Parent() || !_IsShadow())
 		return B_BAD_VALUE;
-	status_t error = _kern_resize_partition(_ShadowID(), newOffset, force);
+	status_t error = _kern_resize_partition(_ShadowID(), _ChangeCounter(),
+											newOffset, force);
 	if (error == B_OK)
 		error = Device()->Update();
 	return error;
@@ -582,7 +589,8 @@ bool
 BPartition::CanSetName() const
 {
 	return (fPartitionData && Parent() && _IsShadow()
-			&& _kern_supports_setting_partition_name(_ShadowID()));
+			&& _kern_supports_setting_partition_name(_ShadowID(),
+													 _ChangeCounter()));
 }
 
 // ValidateSetName
@@ -591,7 +599,8 @@ BPartition::ValidateSetName(char *name) const
 {
 	if (!fPartitionData || IsDevice() || !Parent() || !_IsShadow() || !name)
 		return B_BAD_VALUE;
-	return _kern_validate_set_partition_name(_ShadowID(), name);
+	return _kern_validate_set_partition_name(_ShadowID(), _ChangeCounter(),
+											 name);
 }
 
 // SetName
@@ -600,7 +609,8 @@ BPartition::SetName(const char *name)
 {
 	if (!fPartitionData || IsDevice() || !Parent() || !_IsShadow() || !name)
 		return B_BAD_VALUE;
-	status_t error = _kern_set_partition_name(_ShadowID(), name);
+	status_t error = _kern_set_partition_name(_ShadowID(), _ChangeCounter(),
+											  name);
 	if (error == B_OK)
 		error = Device()->Update();
 	return error;
@@ -612,6 +622,7 @@ BPartition::CanSetContentName(bool *whileMounted) const
 {
 	return (fPartitionData && _IsShadow()
 			&& _kern_supports_setting_partition_content_name(_ShadowID(),
+															 _ChangeCounter(),
 															 whileMounted));
 }
 
@@ -621,7 +632,8 @@ BPartition::ValidateSetContentName(char *name) const
 {
 	if (!fPartitionData || !_IsShadow() || !name)
 		return B_BAD_VALUE;
-	return _kern_validate_set_partition_content_name(_ShadowID(), name);
+	return _kern_validate_set_partition_content_name(_ShadowID(),
+													 _ChangeCounter(), name);
 }
 
 // SetContentName
@@ -630,7 +642,8 @@ BPartition::SetContentName(const char *name)
 {
 	if (!fPartitionData || !_IsShadow() || !name)
 		return B_BAD_VALUE;
-	status_t error = _kern_set_partition_content_name(_ShadowID(), name);
+	status_t error = _kern_set_partition_content_name(_ShadowID(),
+													  _ChangeCounter(), name);
 	if (error == B_OK)
 		error = Device()->Update();
 	return error;
@@ -641,7 +654,8 @@ bool
 BPartition::CanSetType() const
 {
 	return (fPartitionData && Parent() && _IsShadow()
-			&& _kern_supports_setting_partition_type(_ShadowID()));
+			&& _kern_supports_setting_partition_type(_ShadowID(),
+													 _ChangeCounter()));
 }
 
 // ValidateSetType
@@ -650,7 +664,8 @@ BPartition::ValidateSetType(const char *type) const
 {
 	if (!fPartitionData || IsDevice() || !Parent() || !_IsShadow() || !type)
 		return B_BAD_VALUE;
-	return _kern_validate_set_partition_type(_ShadowID(), type);
+	return _kern_validate_set_partition_type(_ShadowID(), _ChangeCounter(),
+											 type);
 }
 
 // SetType
@@ -659,7 +674,8 @@ BPartition::SetType(const char *type)
 {
 	if (!fPartitionData || IsDevice() || !Parent() || !_IsShadow() || !type)
 		return B_BAD_VALUE;
-	status_t error = _kern_set_partition_type(_ShadowID(), type);
+	status_t error = _kern_set_partition_type(_ShadowID(), _ChangeCounter(),
+											  type);
 	if (error == B_OK)
 		error = Device()->Update();
 	return error;
@@ -670,7 +686,8 @@ bool
 BPartition::CanEditParameters() const
 {
 	return (fPartitionData && Parent() && _IsShadow()
-			&& _kern_supports_setting_partition_parameters(_ShadowID()));
+			&& _kern_supports_setting_partition_parameters(_ShadowID(),
+														   _ChangeCounter()));
 }
 
 // GetParameterEditor
@@ -687,7 +704,9 @@ BPartition::SetParameters(const char *parameters)
 {
 	if (!fPartitionData || IsDevice() || !Parent() || !_IsShadow())
 		return B_BAD_VALUE;
-	status_t error = _kern_set_partition_parameters(_ShadowID(), parameters);
+	status_t error = _kern_set_partition_parameters(_ShadowID(),
+													_ChangeCounter(),
+													parameters);
 	if (error == B_OK)
 		error = Device()->Update();
 	return error;
@@ -699,7 +718,7 @@ BPartition::CanEditContentParameters(bool *whileMounted) const
 {
 	return (fPartitionData && _IsShadow()
 			&& _kern_supports_setting_partition_content_parameters(
-					_ShadowID(), whileMounted));
+					_ShadowID(), _ChangeCounter(), whileMounted));
 }
 
 // GetContentParameterEditor
@@ -717,6 +736,7 @@ BPartition::SetContentParameters(const char *parameters)
 	if (!fPartitionData || !_IsShadow())
 		return B_BAD_VALUE;
 	status_t error = _kern_set_partition_content_parameters(_ShadowID(),
+															_ChangeCounter(),
 															parameters);
 	if (error == B_OK)
 		error = Device()->Update();
@@ -728,7 +748,9 @@ bool
 BPartition::CanInitialize(const char *diskSystem) const
 {
 	return (fPartitionData && diskSystem && _IsShadow()
-			&& _kern_supports_initializing_partition(_ShadowID(), diskSystem));
+			&& _kern_supports_initializing_partition(_ShadowID(),
+													 _ChangeCounter(),
+													 diskSystem));
 }
 
 // GetInitializationParameterEditor
@@ -747,8 +769,8 @@ BPartition::ValidateInitialize(const char *diskSystem, char *name,
 {
 	if (!fPartitionData || !_IsShadow() || !diskSystem || !name)
 		return B_BAD_VALUE;
-	return _kern_validate_initialize_partition(_ShadowID(), diskSystem, name,
-											   parameters);
+	return _kern_validate_initialize_partition(_ShadowID(), _ChangeCounter(),
+											   diskSystem, name, parameters);
 }
 
 // Initialize
@@ -758,8 +780,8 @@ BPartition::Initialize(const char *diskSystem, const char *name,
 {
 	if (!fPartitionData || !_IsShadow() || !diskSystem || !name)
 		return B_BAD_VALUE;
-	status_t error = _kern_initialize_partition(_ShadowID(), diskSystem, name,
-												parameters);
+	status_t error = _kern_initialize_partition(_ShadowID(), _ChangeCounter(),
+												diskSystem, name, parameters);
 	if (error == B_OK)
 		error = Device()->Update();
 	return error;
@@ -770,7 +792,8 @@ bool
 BPartition::CanCreateChild() const
 {
 	return (fPartitionData && _IsShadow()
-			&& _kern_supports_creating_child_partition(_ShadowID()));
+			&& _kern_supports_creating_child_partition(_ShadowID(),
+													   _ChangeCounter()));
 }
 
 // GetChildCreationParameterEditor
@@ -789,8 +812,9 @@ BPartition::ValidateCreateChild(off_t *offset, off_t *size, const char *type,
 {
 	if (!fPartitionData || !_IsShadow() || !offset || !size || !type)
 		return B_BAD_VALUE;
-	return _kern_validate_create_child_partition(_ShadowID(), offset, size,
-												 type, parameters);
+	return _kern_validate_create_child_partition(_ShadowID(), _ChangeCounter(),
+												 offset, size, type,
+												 parameters);
 }
 
 // CreateChild
@@ -802,8 +826,9 @@ BPartition::CreateChild(off_t offset, off_t size, const char *type,
 		return B_BAD_VALUE;
 	// send the request
 	partition_id childID = -1;
-	status_t error = _kern_create_child_partition(_ShadowID(), offset, size,
-												  type, parameters, &childID);
+	status_t error = _kern_create_child_partition(_ShadowID(),
+							_ChangeCounter(), offset, size, type, parameters,
+							&childID);
 	// update the device
 	if (error == B_OK)
 		error = Device()->Update();
@@ -822,7 +847,8 @@ BPartition::CanDeleteChild(int32 index) const
 {
 	BPartition *child = ChildAt(index);
 	return (child && child->_IsShadow()
-			&& _kern_supports_deleting_child_partition(child->_ShadowID()));
+			&& _kern_supports_deleting_child_partition(child->_ShadowID(),
+					child->_ChangeCounter()));
 }
 
 // DeleteChild
@@ -833,7 +859,8 @@ BPartition::DeleteChild(int32 index)
 	if (!fPartitionData || !_IsShadow() || !child)
 		return B_BAD_VALUE;
 	// send the request
-	status_t error = _kern_delete_partition(child->_ShadowID());
+	status_t error = _kern_delete_partition(child->_ShadowID(),
+											child->_ChangeCounter());
 	// update the device
 	if (error == B_OK)
 		error = Device()->Update();
@@ -902,6 +929,121 @@ BPartition::_Unset()
 	fPartitionData = NULL;
 }
 
+// _RemoveObsoleteDescendants
+status_t
+BPartition::_RemoveObsoleteDescendants(user_partition_data *data,
+									   bool *updated)
+{
+	// remove all children not longer persistent
+	// Not exactly efficient: O(n^2), considering BList::RemoveItem()
+	// O(1). We could do better (O(n*log(n))), when sorting the arrays before,
+	// but then the list access is more random and we had to find the
+	// BPartition to remove, which makes the list operation definitely O(n).
+	int32 count = CountChildren();
+	for (int32 i = count - 1; i >= 0; i--) {
+		BPartition *child = ChildAt(i);
+		bool found = false;
+		for (int32 k = data->child_count - 1; k >= 0; k--) {
+			if (data->children[k]->id == child->ID()) {
+				// found partition: ask it to remove its obsolete descendants
+				found = true;
+				status_t error = child->_RemoveObsoleteDescendants(
+					data->children[k], updated);
+				if (error != B_OK)
+					return error;
+				// set the user data to the BPartition object to find it
+				// quicker later
+				data->children[k]->user_data = child;
+				break;
+			}
+		}
+		// if partition is obsolete, remove it
+		if (!found) {
+			*updated = true;
+			_RemoveChild(i);
+		}
+	}
+	return B_OK;
+}
+
+// compare_string
+static
+int
+compare_string(const char *str1, const char *str2)
+{
+	if (str1 == NULL) {
+		if (str2 == NULL)
+			return 0;
+		return 1;
+	} else if (str2 == NULL)
+		return -1;
+	return strcmp(str1, str2);
+}
+
+// _Update
+status_t
+BPartition::_Update(user_partition_data *data, bool *updated)
+{
+	user_partition_data *oldData = fPartitionData;
+	fPartitionData = data;
+	// check for changes
+	if (data->offset != oldData->offset
+		|| data->size != oldData->size
+		|| data->block_size != oldData->block_size
+		|| data->status != oldData->status
+		|| data->flags != oldData->flags
+		|| data->volume != oldData->volume
+		|| data->disk_system != oldData->disk_system	// not needed
+		|| compare_string(data->name, oldData->name)
+		|| compare_string(data->content_name, oldData->content_name)
+		|| compare_string(data->type, oldData->type)
+		|| compare_string(data->content_type, oldData->content_type)
+		|| compare_string(data->parameters, oldData->parameters)
+		|| compare_string(data->content_parameters,
+						  oldData->content_parameters)) {
+		*updated = true;
+	}
+	// add new children and update existing ones
+	status_t error = B_OK;
+	for (int32 i = 0; i < data->child_count; i++) {
+		user_partition_data *childData = data->children[i];
+		BPartition *child = (BPartition*)childData->user_data;
+		if (child) {
+			// old partition
+			error = child->_Update(childData, updated);
+			if (error != B_OK)
+				return error;
+		} else {
+			// new partition
+			*updated = true;
+			child = new(nothrow) BPartition;
+			if (child) {
+				error = child->_SetTo(fDevice, this, data->children[i]);
+				if (error != B_OK)
+					delete child;
+			} else
+				return B_NO_MEMORY;
+			childData->user_data = child;
+		}
+	}
+	return error;
+}
+
+// _RemoveChild
+void
+BPartition::_RemoveChild(int32 index)
+{
+	int32 count = CountChildren();
+	if (!fPartitionData || index < 0 || index >= count)
+		return;
+	// delete the BPartition and its children
+	delete ChildAt(index);
+	// compact the children array
+	for (int32 i = index + 1; i < count; i++)
+		fPartitionData->children[i - 1] = fPartitionData->children[i];
+	fPartitionData->child_count--;
+}
+
 // _IsShadow
 bool
 BPartition::_IsShadow() const
@@ -923,6 +1065,13 @@ BPartition::_DiskSystem() const
 	return (fPartitionData ? fPartitionData->disk_system : -1);
 }
 
+// _ChangeCounter
+int32
+BPartition::_ChangeCounter() const
+{
+	return (fPartitionData ? fPartitionData->change_counter : -1);
+}
+
 // _CountDescendants
 int32
 BPartition::_CountDescendants() const