diff --git a/ereuse_devicehub/migrations/versions/e93aec8fc41f_added_assigned_action.py b/ereuse_devicehub/migrations/versions/e93aec8fc41f_added_assigned_action.py
index 48a74602..b335256d 100644
--- a/ereuse_devicehub/migrations/versions/e93aec8fc41f_added_assigned_action.py
+++ b/ereuse_devicehub/migrations/versions/e93aec8fc41f_added_assigned_action.py
@@ -62,7 +62,8 @@ def upgrade():
         sa.Column('id', postgresql.UUID(as_uuid=True), nullable=False),
         sa.Column('serial_number', sa.Unicode(), nullable=True,
                   comment='The serial number of the Hard Disk in lower case.'),
-        sa.Column('time', sa.SmallInteger(), nullable=True),
+        sa.Column('usage_time_hdd', sa.Interval(), nullable=True),
+        sa.Column('snapshot_uuid', postgresql.UUID(as_uuid=True), nullable=False),
         sa.ForeignKeyConstraint(['id'], [f'{get_inv()}.action.id'], ),
         sa.PrimaryKeyConstraint('id'),
         schema=f'{get_inv()}'
diff --git a/ereuse_devicehub/resources/action/models.py b/ereuse_devicehub/resources/action/models.py
index 95c2676b..0ba94a91 100644
--- a/ereuse_devicehub/resources/action/models.py
+++ b/ereuse_devicehub/resources/action/models.py
@@ -10,6 +10,7 @@ to a structure based on:
 Within the above general classes are subclasses in A order.
 """
 
+import copy
 from collections import Iterable
 from contextlib import suppress
 from datetime import datetime, timedelta, timezone
@@ -1301,7 +1302,8 @@ class Live(JoinedWithOneDeviceMixin, ActionWithOneDevice):
     """
     serial_number = Column(Unicode(), check_lower('serial_number'))
     serial_number.comment = """The serial number of the Hard Disk in lower case."""
-    time = Column(SmallInteger, nullable=False)
+    usage_time_hdd = Column(Interval, nullable=True)
+    snapshot_uuid = Column(UUID(as_uuid=True))
 
     @property
     def final_user_code(self):
@@ -1311,26 +1313,65 @@ class Live(JoinedWithOneDeviceMixin, ActionWithOneDevice):
         for e in reversed(actions):
             if isinstance(e, Allocate) and e.created < self.created:
                 return e.final_user_code
+        return ''
 
     @property
-    def hours_of_use(self):
+    def usage_time_allocate(self):
         """Show how many hours is used one device from the last check"""
-        actions = self.device.actions
-        actions.sort(key=lambda x: x.created)
-        for e in reversed(actions):
-            if isinstance(e, Snapshot) and e.created < self.created:
-                return self.time - self.get_last_power_cycle(e)
+        self.sort_actions()
+        if self.usage_time_hdd is None:
+            return self.last_usage_time_allocate()
 
+        delta_zero = timedelta(0)
+        diff_time = self.diff_time()
+        if diff_time is None:
+            return delta_zero
+
+        if diff_time < delta_zero:
+            return delta_zero
+        return diff_time
+
+    def sort_actions(self):
+        self.actions = copy.copy(self.device.actions)
+        self.actions.sort(key=lambda x: x.created)
+        self.actions.reverse()
+
+    def last_usage_time_allocate(self):
+        """If we don't have self.usage_time_hdd then we need search the last
+           usage_time_allocate valid"""
+        for e in self.actions:
             if isinstance(e, Live) and e.created < self.created:
-                return self.time - e.time
+                if not e.usage_time_allocate:
+                    continue
+                return e.usage_time_allocate
+        return timedelta(0)
 
-    def get_last_power_cycle(self, snapshot):
+    def diff_time(self):
+        for e in self.actions:
+            if e.created > self.created:
+                continue
+
+            if isinstance(e, Snapshot):
+                last_time = self.get_last_lifetime(e)
+                if not last_time:
+                    continue
+                return self.usage_time_hdd - last_time
+
+            if isinstance(e, Live):
+                if e.snapshot_uuid == self.snapshot_uuid:
+                    continue
+
+                if not e.usage_time_hdd:
+                    continue
+                return self.usage_time_hdd - e.usage_time_hdd
+        return None
+
+    def get_last_lifetime(self, snapshot):
         for a in snapshot.actions:
             if a.type == 'TestDataStorage' and a.device.serial_number == self.serial_number:
-                return a.power_cycle_count
+                return a.lifetime
+        return None
 
-        return 0
-                
 
 class Organize(JoinedTableMixin, ActionWithMultipleDevices):
     """The act of manipulating/administering/supervising/controlling
diff --git a/ereuse_devicehub/resources/action/schemas.py b/ereuse_devicehub/resources/action/schemas.py
index c4aeeca0..71eb8224 100644
--- a/ereuse_devicehub/resources/action/schemas.py
+++ b/ereuse_devicehub/resources/action/schemas.py
@@ -414,8 +414,9 @@ class Live(ActionWithOneDevice):
     __doc__ = m.Live.__doc__
     final_user_code = SanitizedStr(data_key="finalUserCode", dump_only=True)
     serial_number = SanitizedStr(data_key="serialNumber", dump_only=True)
-    time = Integer(dump_only=False)
-    hours_of_use = Integer(dump_only=False)
+    usage_time_hdd = TimeDelta(data_key="usageTimeHdd", precision=TimeDelta.HOURS, dump_only=True)
+    usage_time_allocate = TimeDelta(data_key="usageTimeAllocate", 
+                                    precision=TimeDelta.HOURS, dump_only=True)
 
 
 class Organize(ActionWithMultipleDevices):
diff --git a/ereuse_devicehub/resources/action/views.py b/ereuse_devicehub/resources/action/views.py
index e3dbc8fd..a6aa108e 100644
--- a/ereuse_devicehub/resources/action/views.py
+++ b/ereuse_devicehub/resources/action/views.py
@@ -3,7 +3,7 @@
 import os
 import json
 import shutil
-from datetime import datetime
+from datetime import datetime, timedelta
 from distutils.version import StrictVersion
 from uuid import UUID
 from flask.json import jsonify
@@ -12,6 +12,7 @@ from flask import current_app as app, request, g, redirect
 from sqlalchemy.util import OrderedSet
 from teal.marshmallow import ValidationError
 from teal.resource import View
+from teal.db import ResourceNotFound
 
 from ereuse_devicehub.db import db
 from ereuse_devicehub.query import things_response
@@ -211,38 +212,69 @@ class ActionView(View):
         db.session.commit()
         return ret
 
+    def get_hdd_details(self, snapshot, device):
+        """We get the liftime and serial_number of the disk"""
+        usage_time_hdd = None
+        serial_number = None
+        for hd in snapshot['components']:
+            if not isinstance(hd, DataStorage):
+                continue
+
+            serial_number = hd.serial_number
+            for act in hd.actions:
+                if not act.type == "TestDataStorage":
+                    continue
+                usage_time_hdd = act.lifetime
+                break
+
+            if usage_time_hdd:
+                break
+
+        if not serial_number:
+            "There aren't any disk"
+            raise ResourceNotFound("There aren't any disk in this device {}".format(device))
+        return usage_time_hdd, serial_number
+
     def live(self, snapshot):
         """If the device.allocated == True, then this snapshot create an action live."""
         device = snapshot.get('device')  # type: Computer
         # TODO @cayop dependency of pulls 85 and 83
         # if the pr/85 and pr/83 is merged, then you need change this way for get the device
         if not device.hid or not Device.query.filter(Device.hid==device.hid).count():
-            return
+            return None
 
         device = Device.query.filter(Device.hid==device.hid).one()
 
         if not device.allocated:
-            return
+            return None
 
-        time = 0
-        serial_number = ''
-        for hd in snapshot['components']:
-            if not isinstance(hd, DataStorage):
-                continue
-            for act in hd.actions:
-                if not act.type == "TestDataStorage":
-                    continue
-                time = act.power_cycle_count
-                serial_number = hd.serial_number
+        usage_time_hdd, serial_number = self.get_hdd_details(snapshot, device)
 
-        if not serial_number:
-            return
-
-        data_live = {'time': time,
+        data_live = {'usage_time_hdd': usage_time_hdd,
                      'serial_number': serial_number,
+                     'snapshot_uuid': snapshot['uuid'],
+                     'description': '',
                      'device': device}
 
-        return Live(**data_live)
+        live = Live(**data_live)
+
+        if not usage_time_hdd:
+            warning = f"We don't found any TestDataStorage for disk sn: {serial_number}"
+            live.severity = Severity.Warning
+            live.description = warning
+            return live
+
+        live.sort_actions()
+        diff_time = live.diff_time()
+        if diff_time is None:
+            warning = "Don't exist one previus live or snapshot as reference"
+            live.description += warning
+            live.severity = Severity.Warning
+        elif diff_time < timedelta(0):
+            warning = "The difference with the last live/snapshot is negative"
+            live.description += warning
+            live.severity = Severity.Warning
+        return live
 
     def transfer_ownership(self):
         """Perform a InitTransfer action to change author_id of device"""
diff --git a/ereuse_devicehub/resources/device/sync.py b/ereuse_devicehub/resources/device/sync.py
index 5f13d5a0..28925291 100644
--- a/ereuse_devicehub/resources/device/sync.py
+++ b/ereuse_devicehub/resources/device/sync.py
@@ -154,6 +154,8 @@ class Sync:
         if device.hid:
             with suppress(ResourceNotFound):
                 db_device = Device.query.filter_by(hid=device.hid).one()
+        if db_device and db_device.allocated:
+            raise ResourceNotFound('device is actually allocated {}'.format(device))
         try:
             tags = {Tag.from_an_id(tag.id).one() for tag in device.tags}  # type: Set[Tag]
         except ResourceNotFound:
diff --git a/tests/test_action.py b/tests/test_action.py
index 9572c3eb..cafd392e 100644
--- a/tests/test_action.py
+++ b/tests/test_action.py
@@ -264,15 +264,193 @@ def test_live(user: UserClient, app: Devicehub):
     acer['uuid'] = "490fb8c0-81a1-42e9-95e0-5e7db7038ec3"
     hdd = [c for c in acer['components'] if c['type'] == 'HardDrive'][0]
     hdd_action = [a for a in hdd['actions'] if a['type'] == 'TestDataStorage'][0]
-    hdd_action['powerCycleCount'] += 1000
+    hdd_action['lifetime'] += 1000
     snapshot, _ = user.post(acer, res=models.Snapshot)
     db_device = Device.query.filter_by(id=1).one()
     action_live = [a for a in db_device.actions if a.type == 'Live']
     assert len(action_live) == 1
-    assert action_live[0].time == 6293
-    assert action_live[0].hours_of_use == 1000
+    assert action_live[0].usage_time_hdd == timedelta(hours=hdd_action['lifetime'])
+    assert action_live[0].usage_time_allocate == timedelta(hours=1000)
     assert action_live[0].final_user_code == post_request['finalUserCode']
     assert action_live[0].serial_number == 'wd-wx11a80w7430'
+    assert str(action_live[0].snapshot_uuid) == acer['uuid']
+
+@pytest.mark.mvp
+@pytest.mark.usefixtures(conftest.app_context.__name__)
+def test_live_without_TestDataStorage(user: UserClient, app: Devicehub):
+    """Tests inserting a Live into the database and GETting it.
+       If the live don't have a TestDataStorage, then save live and response None
+    """
+    acer = file('acer.happy.battery.snapshot')
+    snapshot, _ = user.post(acer, res=models.Snapshot)
+    device_id = snapshot['device']['id']
+    db_device = Device.query.filter_by(id=1).one()
+    post_request = {"transaction": "ccc", "name": "John", "endUsers": 1,
+                    "devices": [device_id], "description": "aaa",
+                    "finalUserCode": "abcdefjhi",
+                    "startTime": "2020-11-01T02:00:00+00:00",
+                    "endTime": "2020-12-01T02:00:00+00:00"
+    }
+
+    user.post(res=models.Allocate, data=post_request)
+    acer['uuid'] = "490fb8c0-81a1-42e9-95e0-5e7db7038ec3"
+    actions = [a for a in acer['components'][7]['actions'] if a['type'] != 'TestDataStorage']
+    acer['components'][7]['actions'] = actions
+    live, _ = user.post(acer, res=models.Snapshot)
+    assert live['type'] == 'Live'
+    assert live['serialNumber'] == 'wd-wx11a80w7430'
+    assert live['severity'] == 'Warning'
+    description = "We don't found any TestDataStorage for disk sn: wd-wx11a80w7430"
+    assert live['description'] == description
+    db_live = models.Live.query.filter_by(id=live['id']).one()
+    assert db_live.usage_time_hdd is None
+
+
+@pytest.mark.mvp
+@pytest.mark.usefixtures(conftest.app_context.__name__)
+def test_live_without_hdd_1(user: UserClient, app: Devicehub):
+    """Tests inserting a Live into the database and GETting it.
+       The snapshot have hdd but the live no, and response 404
+    """
+    acer = file('acer.happy.battery.snapshot')
+    snapshot, _ = user.post(acer, res=models.Snapshot)
+    device_id = snapshot['device']['id']
+    db_device = Device.query.filter_by(id=1).one()
+    post_request = {"transaction": "ccc", "name": "John", "endUsers": 1,
+                    "devices": [device_id], "description": "aaa",
+                    "finalUserCode": "abcdefjhi",
+                    "startTime": "2020-11-01T02:00:00+00:00",
+                    "endTime": "2020-12-01T02:00:00+00:00"
+    }
+
+    user.post(res=models.Allocate, data=post_request)
+    acer['uuid'] = "490fb8c0-81a1-42e9-95e0-5e7db7038ec3"
+    components = [a for a in acer['components'] if a['type'] != 'HardDrive']
+    acer['components'] = components
+    response, _ = user.post(acer, res=models.Snapshot, status=404)
+    assert "The There aren't any disk in this device" in response['message']
+
+
+@pytest.mark.mvp
+@pytest.mark.usefixtures(conftest.app_context.__name__)
+def test_live_without_hdd_2(user: UserClient, app: Devicehub):
+    """Tests inserting a Live into the database and GETting it.
+       The snapshot haven't hdd and the live neither, and response 404
+    """
+    acer = file('acer.happy.battery.snapshot')
+    components = [a for a in acer['components'] if a['type'] != 'HardDrive']
+    acer['components'] = components
+    snapshot, _ = user.post(acer, res=models.Snapshot)
+    device_id = snapshot['device']['id']
+    db_device = Device.query.filter_by(id=1).one()
+    post_request = {"transaction": "ccc", "name": "John", "endUsers": 1,
+                    "devices": [device_id], "description": "aaa",
+                    "finalUserCode": "abcdefjhi",
+                    "startTime": "2020-11-01T02:00:00+00:00",
+                    "endTime": "2020-12-01T02:00:00+00:00"
+    }
+
+    user.post(res=models.Allocate, data=post_request)
+    acer['uuid'] = "490fb8c0-81a1-42e9-95e0-5e7db7038ec3"
+    response, _ = user.post(acer, res=models.Snapshot, status=404)
+    assert "The There aren't any disk in this device" in response['message']
+
+
+@pytest.mark.mvp
+@pytest.mark.usefixtures(conftest.app_context.__name__)
+def test_live_without_hdd_3(user: UserClient, app: Devicehub):
+    """Tests inserting a Live into the database and GETting it.
+       The snapshot haven't hdd and the live have, and save the live
+       with usage_time_allocate == 0
+    """
+    acer = file('acer.happy.battery.snapshot')
+    acer['uuid'] = "490fb8c0-81a1-42e9-95e0-5e7db7038ec3"
+    components = [a for a in acer['components'] if a['type'] != 'HardDrive']
+    acer['components'] = components
+    snapshot, _ = user.post(acer, res=models.Snapshot)
+    device_id = snapshot['device']['id']
+    db_device = Device.query.filter_by(id=1).one()
+    post_request = {"transaction": "ccc", "name": "John", "endUsers": 1,
+                    "devices": [device_id], "description": "aaa",
+                    "finalUserCode": "abcdefjhi",
+                    "startTime": "2020-11-01T02:00:00+00:00",
+                    "endTime": "2020-12-01T02:00:00+00:00"
+    }
+
+    user.post(res=models.Allocate, data=post_request)
+    acer = file('acer.happy.battery.snapshot')
+    live, _ = user.post(acer, res=models.Snapshot)
+    assert live['type'] == 'Live'
+    assert live['serialNumber'] == 'wd-wx11a80w7430'
+    assert live['severity'] == 'Warning'
+    description = "Don't exist one previus live or snapshot as reference"
+    assert live['description'] == description
+    db_live = models.Live.query.filter_by(id=live['id']).one()
+    assert str(db_live.usage_time_hdd) == '195 days, 12:00:00'
+    assert str(db_live.usage_time_allocate) == '0:00:00'
+
+
+@pytest.mark.mvp
+@pytest.mark.usefixtures(conftest.app_context.__name__)
+def test_live_with_hdd_with_old_time(user: UserClient, app: Devicehub):
+    """Tests inserting a Live into the database and GETting it.
+       The snapshot hdd have a lifetime higher than lifetime of the live action
+       save the live with usage_time_allocate == 0
+    """
+    acer = file('acer.happy.battery.snapshot')
+    snapshot, _ = user.post(acer, res=models.Snapshot)
+    device_id = snapshot['device']['id']
+    db_device = Device.query.filter_by(id=1).one()
+    post_request = {"transaction": "ccc", "name": "John", "endUsers": 1,
+                    "devices": [device_id], "description": "aaa",
+                    "finalUserCode": "abcdefjhi",
+                    "startTime": "2020-11-01T02:00:00+00:00",
+                    "endTime": "2020-12-01T02:00:00+00:00"
+    }
+
+    user.post(res=models.Allocate, data=post_request)
+    acer = file('acer.happy.battery.snapshot')
+    acer['uuid'] = "490fb8c0-81a1-42e9-95e0-5e7db7038ec3"
+    action = [a for a in acer['components'][7]['actions'] if a['type'] == 'TestDataStorage']
+    action[0]['lifetime'] -= 100
+    live, _ = user.post(acer, res=models.Snapshot)
+    assert live['type'] == 'Live'
+    assert live['serialNumber'] == 'wd-wx11a80w7430'
+    assert live['severity'] == 'Warning'
+    description = "The difference with the last live/snapshot is negative"
+    assert live['description'] == description
+    db_live = models.Live.query.filter_by(id=live['id']).one()
+    assert str(db_live.usage_time_hdd) == '191 days, 8:00:00'
+    assert str(db_live.usage_time_allocate) == '0:00:00'
+
+
+@pytest.mark.mvp
+@pytest.mark.usefixtures(conftest.app_context.__name__)
+def test_live_search_last_allocate(user: UserClient, app: Devicehub):
+    """Tests inserting a Live into the database and GETting it.
+    """
+    acer = file('acer.happy.battery.snapshot')
+    snapshot, _ = user.post(acer, res=models.Snapshot)
+    device_id = snapshot['device']['id']
+    db_device = Device.query.filter_by(id=1).one()
+    post_request = {"transaction": "ccc", "name": "John", "endUsers": 1,
+                    "devices": [device_id], "description": "aaa",
+                    "finalUserCode": "abcdefjhi",
+                    "startTime": "2020-11-01T02:00:00+00:00",
+                    "endTime": "2020-12-01T02:00:00+00:00"
+    }
+
+    user.post(res=models.Allocate, data=post_request)
+    acer['uuid'] = "490fb8c0-81a1-42e9-95e0-5e7db7038ec3"
+    hdd = [c for c in acer['components'] if c['type'] == 'HardDrive'][0]
+    hdd_action = [a for a in hdd['actions'] if a['type'] == 'TestDataStorage'][0]
+    hdd_action['lifetime'] += 1000
+    live, _ = user.post(acer, res=models.Snapshot)
+    acer['uuid'] = "490fb8c0-81a1-42e9-95e0-5e7db7038ec4"
+    actions = [a for a in acer['components'][7]['actions'] if a['type'] != 'TestDataStorage']
+    acer['components'][7]['actions'] = actions
+    live, _ = user.post(acer, res=models.Snapshot)
+    assert live['usageTimeAllocate'] == 1000
 
 
 @pytest.mark.mvp