diff --git a/base/fs/partitionmaps/abstract.py b/base/fs/partitionmaps/abstract.py
index 5871027..a7ea15b 100644
--- a/base/fs/partitionmaps/abstract.py
+++ b/base/fs/partitionmaps/abstract.py
@@ -70,7 +70,7 @@ class AbstractPartitionMap(FSMProxy):
 	def _before_unmap(self, event):
 		volume = event.volume
 		for partition in self.partitions:
-			if partition.is_blocking():
+			if partition.is_state('mounted'):
 				msg = 'The partition {partition} prevents the unmap procedure'.format(partition=partition)
 				raise PartitionError(msg)
 		log_check_call(['/sbin/kpartx', '-d', volume.device_path])
diff --git a/base/fs/partitionmaps/gpt.py b/base/fs/partitionmaps/gpt.py
index b884bd9..0b2e8bf 100644
--- a/base/fs/partitionmaps/gpt.py
+++ b/base/fs/partitionmaps/gpt.py
@@ -7,14 +7,15 @@ from common.tools import log_check_call
 class GPTPartitionMap(AbstractPartitionMap):
 
 	def __init__(self, data):
-		self.boot = None
-		self.swap = None
+		self.partitions = []
 		if 'boot' in data:
 			self.boot = GPTPartition(data['boot']['size'], data['boot']['filesystem'], 'boot', None)
+			self.partitions.append(self.boot)
 		self.root = GPTPartition(data['root']['size'], data['root']['filesystem'], 'root', self.boot)
+		self.partitions.append(self.root)
 		if 'swap' in data:
 			self.swap = GPTSwapPartition(data['swap']['size'], self.root)
-		self.partitions = filter(lambda p: p is not None, [self.boot, self.root, self.swap])
+			self.partitions.append(self.swap)
 
 		super(GPTPartitionMap, self).__init__()
 
@@ -26,7 +27,7 @@ class GPTPartitionMap(AbstractPartitionMap):
 			partition.create(volume)
 
 		boot_idx = self.root.get_index()
-		if self.boot is not None:
+		if hasattr(self, 'boot'):
 			boot_idx = self.boot.get_index()
 		log_check_call(['/sbin/parted', '--script', volume.device_path,
 		                '--', 'set ' + str(boot_idx) + ' boot on'])
diff --git a/base/fs/partitionmaps/mbr.py b/base/fs/partitionmaps/mbr.py
index 0bc4cfa..0d4b50f 100644
--- a/base/fs/partitionmaps/mbr.py
+++ b/base/fs/partitionmaps/mbr.py
@@ -7,14 +7,15 @@ from common.tools import log_check_call
 class MBRPartitionMap(AbstractPartitionMap):
 
 	def __init__(self, data):
-		self.boot = None
-		self.swap = None
+		self.partitions = []
 		if 'boot' in data:
 			self.boot = MBRPartition(data['boot']['size'], data['boot']['filesystem'], None)
+			self.partitions.append(self.boot)
 		self.root = MBRPartition(data['root']['size'], data['root']['filesystem'], self.boot)
+		self.partitions.append(self.root)
 		if 'swap' in data:
 			self.swap = MBRSwapPartition(data['swap']['size'], self.root)
-		self.partitions = filter(lambda p: p is not None, [self.boot, self.root, self.swap])
+			self.partitions.append(self.swap)
 
 		super(MBRPartitionMap, self).__init__()
 
@@ -26,7 +27,7 @@ class MBRPartitionMap(AbstractPartitionMap):
 			partition.create(volume)
 
 		boot_idx = self.root.get_index()
-		if self.boot is not None:
+		if hasattr(self, 'boot'):
 			boot_idx = self.boot.get_index()
 		log_check_call(['/sbin/parted', '--script', volume.device_path,
 		                '--', 'set ' + str(boot_idx) + ' boot on'])
diff --git a/base/fs/partitionmaps/none.py b/base/fs/partitionmaps/none.py
index 1b2cfd8..cbca282 100644
--- a/base/fs/partitionmaps/none.py
+++ b/base/fs/partitionmaps/none.py
@@ -9,7 +9,7 @@ class NoPartitions(object):
 		self.partitions = [self.root]
 
 	def is_blocking(self):
-		return self.root.is_blocking()
+		return self.root.is_state('mounted')
 
 	def get_total_size(self):
 		return self.root.size
diff --git a/base/fs/partitions/abstract.py b/base/fs/partitions/abstract.py
index 14a0b1a..9f80618 100644
--- a/base/fs/partitions/abstract.py
+++ b/base/fs/partitions/abstract.py
@@ -22,9 +22,6 @@ class AbstractPartition(FSMProxy):
 		cfg = {'initial': 'nonexistent', 'events': self.events, 'callbacks': {}}
 		super(AbstractPartition, self).__init__(cfg)
 
-	def is_blocking(self):
-		return self.is_state('mounted')
-
 	def get_uuid(self):
 		[uuid] = log_check_call(['/sbin/blkid', '-s', 'UUID', '-o', 'value', self.device_path])
 		return uuid
diff --git a/base/fs/partitions/base.py b/base/fs/partitions/base.py
index 65d97ee..8986285 100644
--- a/base/fs/partitions/base.py
+++ b/base/fs/partitions/base.py
@@ -18,9 +18,6 @@ class BasePartition(AbstractPartition):
 		self.previous = previous
 		super(BasePartition, self).__init__(size, filesystem)
 
-	def is_blocking(self):
-		return self.get_state() in ['mapped', 'mounted', 'formatted']
-
 	def get_index(self):
 		if self.previous is None:
 			return 1
diff --git a/common/tasks/partitioning.py b/common/tasks/partitioning.py
index eeca38d..a0ec17b 100644
--- a/common/tasks/partitioning.py
+++ b/common/tasks/partitioning.py
@@ -9,7 +9,7 @@ class PartitionVolume(Task):
 	phase = phases.volume_preparation
 
 	def run(self, info):
-		info.volume.partition_map.create()
+		info.volume.partition_map.create(info.volume)
 
 
 class MapPartitions(Task):
@@ -19,7 +19,7 @@ class MapPartitions(Task):
 	after = [PartitionVolume]
 
 	def run(self, info):
-		info.volume.partition_map.map()
+		info.volume.partition_map.map(info.volume)
 
 
 class UnmapPartitions(Task):
@@ -29,4 +29,4 @@ class UnmapPartitions(Task):
 	after = [filesystem.UnmountRoot]
 
 	def run(self, info):
-		info.volume.partition_map.unmap()
+		info.volume.partition_map.unmap(info.volume)
diff --git a/providers/virtualbox/tasks/boot.py b/providers/virtualbox/tasks/boot.py
index 4577e92..8527030 100644
--- a/providers/virtualbox/tasks/boot.py
+++ b/providers/virtualbox/tasks/boot.py
@@ -30,9 +30,9 @@ class ConfigureGrub(Task):
 				p_map.boot.unmount()
 			p_map.root.unmount()
 			if not isinstance(p_map, NoPartitions):
-				p_map.unmap()
+				p_map.unmap(info.volume)
 				fn()
-				p_map.map()
+				p_map.map(info.volume)
 			else:
 				fn()
 				p_map.root.device_path = info.volume.device_path
@@ -70,4 +70,4 @@ class ConfigureGrub(Task):
 			raise e
 
 		if isinstance(info.volume, LoopbackVolume):
-			remount(info.volume, info.volume.unlink_dm_node)
+			remount(info.volume.unlink_dm_node)