diff --git a/libraries/DataFlash/DataFlash.cpp b/libraries/DataFlash/DataFlash.cpp
index 616c7a4f3b..500693e1fe 100644
--- a/libraries/DataFlash/DataFlash.cpp
+++ b/libraries/DataFlash/DataFlash.cpp
@@ -18,6 +18,20 @@ const AP_Param::GroupInfo DataFlash_Class::var_info[] = {
     // @User: Standard
     AP_GROUPINFO("_FILE_BUFSIZE",  1, DataFlash_Class, _params.file_bufsize,       16),
 
+    // @Param: _DISARMED
+    // @DisplayName: Enable logging while disarmed
+    // @Description: If LOG_DISARMED is set to 1 then logging will be enabled while disarmed. This can make for very large logfiles but can help a lot when tracking down startup issues
+    // @Values:0:Disabled,1:Enabled
+    // @User: Standard
+    AP_GROUPINFO("_DISARMED",  2, DataFlash_Class, _params.log_disarmed,       0),
+
+    // @Param: _REPLAY
+    // @DisplayName: Enable logging of information needed for Replay
+    // @Description: If LOG_REPLAY is set to 1 then the EKF2 state estimator will log detailed information needed for diagnosing problems with the Kalman filter. It is suggested that you also raise LOG_FILE_BUFSIZE to give more buffer space for logging and use a high quality microSD card to ensure no sensor data is lost
+    // @Values:0:Disabled,1:EnabledIMU1,3:EnabledIMU1andIMU2
+    // @User: Standard
+    AP_GROUPINFO("_REPLAY",  3, DataFlash_Class, _params.log_replay,       0),
+    
     AP_GROUPEND
 };
 
diff --git a/libraries/DataFlash/DataFlash.h b/libraries/DataFlash/DataFlash.h
index f9ca1bbae8..af248f4739 100644
--- a/libraries/DataFlash/DataFlash.h
+++ b/libraries/DataFlash/DataFlash.h
@@ -174,6 +174,10 @@ public:
 
     // number of blocks that have been dropped
     uint32_t num_dropped(void) const;
+
+    // accesss to public parameters
+    bool log_while_disarmed(void) const { return _params.log_disarmed != 0; }
+    uint8_t log_replay(void) const { return _params.log_replay; }
     
     vehicle_startup_message_Log_Writer _vehicle_messages;
 
@@ -182,6 +186,8 @@ public:
     struct {
         AP_Int8 backend_types;
         AP_Int8 file_bufsize; // in kilobytes
+        AP_Int8 log_disarmed;
+        AP_Int8 log_replay;
     } _params;
 
     const struct LogStructure *structure(uint16_t num) const;