diff --git a/backive/backive_service b/backive/backive_service
old mode 100644
new mode 100755
index d71e5d4..ff0b177
--- a/backive/backive_service
+++ b/backive/backive_service
@@ -7,16 +7,16 @@ import sys
 import os
 import asyncio
 import logging
+import json
 from backive.core.events import EventInterface
+from backive.core.scheduler import Scheduler
 from backive.config.config import Config
 
 
 rootlogger = logging.getLogger()
 rootlogger.setLevel(logging.DEBUG)
 consoleHandler = logging.StreamHandler(sys.stdout)
-fileHandler = logging.FileHandler("/var/log/backive/backive.log")
-if not os.path.exists("/var/log/backive"):
-    os.makedirs("/var/log/backive")
+fileHandler = logging.FileHandler("backive.log")
 rootlogger.addHandler(consoleHandler)
 rootlogger.addHandler(fileHandler)
 
@@ -29,7 +29,14 @@ class Backive:
         self._events = None
 
     async def callback(self, data=None):
-        print("Callback: {}".format(str(data)))
+        data_dict = json.loads(data)
+        uuid = data_dict.get("ID_FS_UUID", None)
+        print("UUID: %s" % uuid)
+        if uuid:
+            backups = self._config.get_backups_by_device(uuid)
+            for backup in backups:
+                backup.run()
+
 
     def serve(self):
         loop = asyncio.get_event_loop()
diff --git a/backive/backive_udev b/backive/backive_udev
old mode 100644
new mode 100755
index 12204d7..d1e3732
--- a/backive/backive_udev
+++ b/backive/backive_udev
@@ -4,12 +4,20 @@
 Callable script for udev rules.
 """
 import socket
-import sys
+import os
+import json
 
-unix_socket = "/tmp/backive/backive.sock"
 
-sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-sock.connect(unix_socket)
-if len(sys.argv) > 1:
-    sock.send(sys.argv[1].encode())
-sock.close()
+with open("/tmp/backive/udev.log", "a") as stream:
+    stream.write("udev run...")
+    for k, v in os.environ.items():
+        stream.write("{k}: {v}\n".format(k=k, v=v))
+
+    unix_socket = "/tmp/backive/backive.sock"
+    try:
+        sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        sock.connect(unix_socket)
+        sock.send(json.dumps(dict(os.environ)).encode())
+        sock.close()
+    except Exception as e:
+        stream.write("Exception occurred: {}".format(str(e)))
diff --git a/backive/config/schema.yml b/backive/config/schema.yml
index 2ae12fa..7624a46 100644
--- a/backive/config/schema.yml
+++ b/backive/config/schema.yml
@@ -45,13 +45,11 @@ definitions:
                         type: string
                         # target device name
                     frequency:
-                        type: string
-                        # in numbers? days? weeks?
-                        # or just strings like
+                        # JUST DAYS!
+                        type: integer
+                        # other possibilities in the future
                         # weekly, biweekly, monthly, yearly
                         # 7d, 2w, 1m, 1y (this needs parser)
-                        #
-                        # No frequency means no reminder and the backup is always started when the device is available, but not more than once a day!
                     script:
                         type: string
                         # MVP just executes a script, nothing else
@@ -73,6 +71,7 @@ definitions:
                     - to
                     - target_device
                     - script
+                    - frequency
                 additionalProperties: false
     preferences_section:
         type: object
diff --git a/backive/core/backup.py b/backive/core/backup.py
index 2d02fba..72c9a3c 100644
--- a/backive/core/backup.py
+++ b/backive/core/backup.py
@@ -1,4 +1,5 @@
 import os
+import logging
 
 
 class Backup:
@@ -8,13 +9,13 @@ class Backup:
 
     @classmethod
     def instance(cls, name, config=None):
+        logging.debug("Backup instance created (%s)", name)
         return Backup(name, config)
 
     def get_frequency(self):
         return self.config.get("frequency", None)
 
     def run(self):
-
         if self.config.get("scripts", None):
             pass
 
diff --git a/backive/core/device.py b/backive/core/device.py
index 91de95b..c37c356 100644
--- a/backive/core/device.py
+++ b/backive/core/device.py
@@ -1,4 +1,5 @@
 import os
+import logging
 import backive.config.config as cfg
 
 
@@ -11,6 +12,7 @@ class Device:
 
     @classmethod
     def instance(cls, name, config=None):
+        logging.debug("Device instance created (%s)", name)
         return Device(name, config)
 
     @classmethod
diff --git a/backive/core/scheduler.py b/backive/core/scheduler.py
index 7271ed5..ee1aba9 100644
--- a/backive/core/scheduler.py
+++ b/backive/core/scheduler.py
@@ -57,7 +57,21 @@ class Scheduler():
         self.save()
 
     def should_run(self, name):
-        pass
+        runs = self.__data.get("runs", dict())
+        if name not in runs:
+            return True
+        if name in runs:
+            backups = self.__data.get("backups", dict())
+            if name in backups:
+                frequency = backups[name]
+            last_ts = runs[name][-1]
+            now = datetime.now()
+            last = datetime.fromisoformat(last_ts)
+            diff = now - last
+            days = diff.days
+            if days > frequency and days >= 1:
+                return True
+        return False
 
     def get_overtimed(self):
         return list()