diff --git a/control-connector/src/main/java/org/polypheny/control/client/PolyphenyControlConnector.java b/control-connector/src/main/java/org/polypheny/control/client/PolyphenyControlConnector.java
index 2de9e2c..bd388a7 100644
--- a/control-connector/src/main/java/org/polypheny/control/client/PolyphenyControlConnector.java
+++ b/control-connector/src/main/java/org/polypheny/control/client/PolyphenyControlConnector.java
@@ -174,6 +174,11 @@ String getStatus() {
     }
 
 
+    boolean checkForAnyRunningPolyphenyInstances() {
+        return Boolean.parseBoolean( executeGet( "/control/checkAnyRunningPolyphenyInstances" ) );
+    }
+
+
     private String executeGet( String command ) {
         HttpResponse<String> httpResponse;
         try {
diff --git a/src/main/java/org/polypheny/control/control/Control.java b/src/main/java/org/polypheny/control/control/Control.java
index b228489..4ca48c8 100644
--- a/src/main/java/org/polypheny/control/control/Control.java
+++ b/src/main/java/org/polypheny/control/control/Control.java
@@ -158,6 +158,11 @@ public void getStatus( Context ctx ) {
     }
 
 
+    public void checkAnyRunningPolyphenyInstances( Context ctx ) {
+        ctx.result( ServiceManager.getPidOfRunningPolyphenyInstances().size() + "" );
+    }
+
+
     public void getVersion( Context ctx ) {
         ctx.result( gson.toJson( ServiceManager.getVersion() ) );
     }
diff --git a/src/main/java/org/polypheny/control/control/PolyphenyDbProcess.java b/src/main/java/org/polypheny/control/control/PolyphenyDbProcess.java
index 5fd53bd..ee41c51 100644
--- a/src/main/java/org/polypheny/control/control/PolyphenyDbProcess.java
+++ b/src/main/java/org/polypheny/control/control/PolyphenyDbProcess.java
@@ -263,7 +263,6 @@ public void killForcibly() {
                 } catch ( InterruptedException e ) {
                     log.warn( "Interrupted while waiting for kill to finish." );
                 }
-
             } else {
                 super.process.destroyForcibly();
             }
diff --git a/src/main/java/org/polypheny/control/control/ServiceManager.java b/src/main/java/org/polypheny/control/control/ServiceManager.java
index 788232a..021299f 100644
--- a/src/main/java/org/polypheny/control/control/ServiceManager.java
+++ b/src/main/java/org/polypheny/control/control/ServiceManager.java
@@ -179,10 +179,10 @@ public static boolean start( final ClientCommunicationStream clientCommunication
             //
 
             LinkedList<String> javaOptionsFull = new LinkedList<>( javaOptions );
-            String applicationConfFileName = new File( new File( workingDir ), "config" ).getAbsolutePath() + File.separator + "application.conf";
+            /*String applicationConfFileName = new File( new File( workingDir ), "config" ).getAbsolutePath() + File.separator + "application.conf";
             if ( new File( applicationConfFileName ).exists() ) {
                 javaOptionsFull.addFirst( "-Dconfig.file=" + applicationConfFileName );
-            }
+            }*/
             javaOptionsFull.addFirst( "-Xmx" + javaMaximumHeapSize + "G" );
 
             // Build list of arguments
@@ -992,6 +992,32 @@ public static Object getStatus() {
     }
 
 
+    public static List<Integer> getPidOfRunningPolyphenyInstances() {
+        if ( SystemUtils.IS_OS_WINDOWS ) {
+            throw new RuntimeException( "This operation is not supported on Windows" );
+        }
+        try {
+            List<Integer> pids = new ArrayList<>();
+            Process process = Runtime.getRuntime().exec( "ps aux|grep org.polypheny.db.PolyphenyDb|grep -v grep|awk '{print $2}'" );
+            try ( BufferedReader input = new BufferedReader( new InputStreamReader( process.getInputStream() ) ) ) {
+                String line;
+                while ( (line = input.readLine()) != null ) {
+                    int id = Integer.parseInt( line );
+                    if ( polyphenyDbProcess != null && id != polyphenyDbProcess.getPid() ) {
+                        log.warn( "There is a running Polypheny instance, but it has a unknown PID: {}", id );
+                    }
+                    pids.add( id );
+                }
+            } catch ( IOException e ) {
+                throw new RuntimeException( "IOException while checking if there are other instances of Polypheny.", e );
+            }
+            return pids;
+        } catch ( IOException e ) {
+            throw new RuntimeException( "IOException while checking if there are other instances of Polypheny.", e );
+        }
+    }
+
+
     private static boolean existsLocalBranchWithName( Git git, String branchName ) throws GitAPIException {
         List<Ref> branches = git.branchList().call();
         for ( Ref ref : branches ) {
diff --git a/src/main/java/org/polypheny/control/httpinterface/Server.java b/src/main/java/org/polypheny/control/httpinterface/Server.java
index ed55310..ec79e51 100644
--- a/src/main/java/org/polypheny/control/httpinterface/Server.java
+++ b/src/main/java/org/polypheny/control/httpinterface/Server.java
@@ -146,6 +146,7 @@ public Server( Control control, int port ) {
         javalin.get( "/control/pdbBranches", control::getAvailablePdbBranches );
         javalin.get( "/control/puiBranches", control::getAvailablePuiBranches );
         javalin.post( "/control/purgePolyphenyFolder", control::purgePolyphenyFolder );
+        javalin.get( "/control/checkAnyRunningPolyphenyInstances", control::checkAnyRunningPolyphenyInstances );
 
         // /polyfier
         javalin.post( "/polyfier/start", control::polyfierStart );