Fixed a bug that was causing sync-to-disk to fail

sonic-stormond/scripts/stormond

@@ -122,7 +122,7 @@ class DaemonStorage(daemon_base.DaemonBase):
                self.fsio_json_file_loaded = True
 
         except Exception as e:
-            self.log_error("JSON file could not be loaded: {}".format(e))
+            self.log_error("JSON file could not be loaded: {}".format(str(e)))
 
         return
 
@@ -132,7 +132,7 @@ class DaemonStorage(daemon_base.DaemonBase):
 
         self.log_info("Syncing total and latest procfs reads and writes from STATE_DB to JSON file")
 
-        json_file_dict = {}
+        json_file_dict = {disk:{} for disk in self.storage.devices}
         try:
             for device in self.storage.devices:
                 for field in self.statedb_json_sync_fields:
@@ -146,7 +146,7 @@ class DaemonStorage(daemon_base.DaemonBase):
                 self.state_db.hset("{}|{}".format(STORAGE_DEVICE_TABLE,FSSTATS_SYNC_TIME_KEY), "successful_sync_time", str(self.fsio_sync_time))
 
         except Exception as ex:
-            self.log_error("Unable to sync state_db to disk: {}".format(ex))
+            self.log_error("Unable to sync state_db to disk: {}".format(str(ex)))
 
     # Run a sanity check on the state_db. If successful, get total, latest 
     # FSIO reads and writes for each storage device from STATE_DB
@@ -171,7 +171,7 @@ class DaemonStorage(daemon_base.DaemonBase):
 
             self.statedb_storage_info_loaded = True
         except Exception as e:
-            self.log_error("Reading STATE_DB failed with: {}".format(e))
+            self.log_error("Reading STATE_DB failed with: {}".format(str(e)))
 
 
     def _determine_sot(self):