diff --git a/lib/Doctrine/ORM/Tools/Console/Command/ConvertMappingCommand.php b/lib/Doctrine/ORM/Tools/Console/Command/ConvertMappingCommand.php
index 797bc29a8..8c1a8fea1 100644
--- a/lib/Doctrine/ORM/Tools/Console/Command/ConvertMappingCommand.php
+++ b/lib/Doctrine/ORM/Tools/Console/Command/ConvertMappingCommand.php
@@ -63,6 +63,10 @@ class ConvertMappingCommand extends Console\Command\Command
                 'dest-path', InputArgument::REQUIRED,
                 'The path to generate your entities classes.'
             ),
+            new InputOption(
+                'force', null, InputOption::VALUE_NONE,
+                'Force to overwrite existing mapping files.'
+            ),
             new InputOption(
                 'from-database', null, null, 'Whether or not to convert mapping information from existing database.'
             ),
@@ -73,10 +77,24 @@ class ConvertMappingCommand extends Console\Command\Command
             new InputOption(
                 'num-spaces', null, InputOption::VALUE_OPTIONAL,
                 'Defines the number of indentation spaces', 4
-            )
+            ),
         ))
         ->setHelp(<<<EOT
 Convert mapping information between supported formats.
+
+This is an execute <info>one-time</info> command. It should not be necessary for
+you to call this method multiple times, escpecially when using the <comment>--from-database</comment>
+flag.
+
+Converting an existing databsae schema into mapping files only solves about 70-80%
+of the necessary mapping information. Additionally the detection from an existing
+database cannot detect inverse associations, inheritance types,
+entities with foreign keys as primary keys and many of the
+semantical operations on associations such as cascade.
+
+<comment>Hint:</comment> There is no need to convert YAML or XML mapping files to annotations
+every time you make changes. All mapping drivers are first class citizens
+in Doctrine 2 and can be used as runtime mapping for the ORM.
 EOT
         );
     }
@@ -121,6 +139,7 @@ EOT
 
         $cme = new ClassMetadataExporter();
         $exporter = $cme->getExporter($toType, $destPath);
+        $exporter->setOverwriteExistingFiles( ($input->getOption('force') !== false) );
 
         if ($toType == 'annotation') {
             $entityGenerator = new EntityGenerator();
diff --git a/lib/Doctrine/ORM/Tools/Console/Command/GenerateEntitiesCommand.php b/lib/Doctrine/ORM/Tools/Console/Command/GenerateEntitiesCommand.php
index f69b5167f..198db0d6c 100644
--- a/lib/Doctrine/ORM/Tools/Console/Command/GenerateEntitiesCommand.php
+++ b/lib/Doctrine/ORM/Tools/Console/Command/GenerateEntitiesCommand.php
@@ -85,6 +85,23 @@ class GenerateEntitiesCommand extends Console\Command\Command
         ))
         ->setHelp(<<<EOT
 Generate entity classes and method stubs from your mapping information.
+
+If you use the <comment>--update-entities</comment> or <comment>--regenerate-entities</comment> flags your exisiting
+code gets overwritten. The EntityGenerator will only append new code to your
+file and will not delete the old code. However this approach may still be prone
+to error and we suggest you use code repositories such as GIT or SVN to make
+backups of your code.
+
+It makes sense to generate the entity code if you are using entities as Data
+Access Objects only and dont put much additional logic on them. If you are
+however putting much more logic on the entities you should refrain from using
+the entity-generator and code your entities manually.
+
+<error>Important:</error> Even if you specified Inheritance options in your
+XML or YAML Mapping files the generator cannot generate the base and
+child classes for you correctly, because it doesn't know which
+class is supposed to extend which. You have to adjust the entity
+code manually for inheritance to work!
 EOT
         );
     }
diff --git a/lib/Doctrine/ORM/Tools/Export/Driver/AbstractExporter.php b/lib/Doctrine/ORM/Tools/Export/Driver/AbstractExporter.php
index 983d0f69d..467332b64 100644
--- a/lib/Doctrine/ORM/Tools/Export/Driver/AbstractExporter.php
+++ b/lib/Doctrine/ORM/Tools/Export/Driver/AbstractExporter.php
@@ -23,6 +23,7 @@
 namespace Doctrine\ORM\Tools\Export\Driver;
 
 use Doctrine\ORM\Mapping\ClassMetadataInfo;
+use Doctrine\ORM\Tools\Export\ExportException;
 
 /**
  * Abstract base class which is to be used for the Exporter drivers
@@ -39,12 +40,18 @@ abstract class AbstractExporter
     protected $_metadata = array();
     protected $_outputDir;
     protected $_extension;
+    protected $_overwriteExistingFiles = false;
 
     public function __construct($dir = null)
     {
         $this->_outputDir = $dir;
     }
 
+    public function setOverwriteExistingFiles($overwrite)
+    {
+        $this->_overwriteExistingFiles = $overwrite;
+    }
+
     /**
      * Converts a single ClassMetadata instance to the exported format
      * and returns it
@@ -110,6 +117,9 @@ abstract class AbstractExporter
             if ( ! is_dir($dir)) {
                 mkdir($dir, 0777, true);
             }
+            if (file_exists($path) && !$this->_overwriteExistingFiles) {
+                throw ExportException::attemptOverwriteExistingFile($path);
+            }
             file_put_contents($path, $output);
         }
     }
diff --git a/lib/Doctrine/ORM/Tools/Export/ExportException.php b/lib/Doctrine/ORM/Tools/Export/ExportException.php
index 6e7826e44..5ba8bd26b 100644
--- a/lib/Doctrine/ORM/Tools/Export/ExportException.php
+++ b/lib/Doctrine/ORM/Tools/Export/ExportException.php
@@ -15,4 +15,9 @@ class ExportException extends ORMException
     {
         return new self("The mapping driver '$type' does not exist");
     }
+
+    public static function attemptOverwriteExistingFile($file)
+    {
+        return new self("Attempting to overwrite an existing file '".$file."'.");
+    }
 }
\ No newline at end of file
diff --git a/tests/Doctrine/Tests/ORM/Tools/ConvertDoctrine1SchemaTest.php b/tests/Doctrine/Tests/ORM/Tools/ConvertDoctrine1SchemaTest.php
index b944c26d9..c0af3a7f3 100644
--- a/tests/Doctrine/Tests/ORM/Tools/ConvertDoctrine1SchemaTest.php
+++ b/tests/Doctrine/Tests/ORM/Tools/ConvertDoctrine1SchemaTest.php
@@ -69,6 +69,7 @@ class ConvertDoctrine1SchemaTest extends \Doctrine\Tests\OrmTestCase
         $converter = new ConvertDoctrine1Schema(__DIR__ . '/doctrine1schema');
 
         $exporter = $cme->getExporter('yml', __DIR__ . '/convert');
+        $exporter->setOverwriteExistingFiles(true);
         $exporter->setMetadata($converter->getMetadata());
         $exporter->export();
 
@@ -80,8 +81,8 @@ class ConvertDoctrine1SchemaTest extends \Doctrine\Tests\OrmTestCase
         $cmf = new DisconnectedClassMetadataFactory();
         $cmf->setEntityManager($em);
         $metadata = $cmf->getAllMetadata();
-        $profileClass = $metadata[0];
-        $userClass = $metadata[1];
+        $profileClass = $cmf->getMetadataFor('Profile');
+        $userClass = $cmf->getMetadataFor('User');
 
         $this->assertEquals(2, count($metadata));
         $this->assertEquals('Profile', $profileClass->name);
@@ -96,9 +97,12 @@ class ConvertDoctrine1SchemaTest extends \Doctrine\Tests\OrmTestCase
         $this->assertEquals('User', $profileClass->associationMappings['User']['targetEntity']);
 
         $this->assertEquals('username', $userClass->table['uniqueConstraints']['username']['columns'][0]);
+    }
 
-        unlink(__DIR__ . '/convert/User.dcm.yml');
-        unlink(__DIR__ . '/convert/Profile.dcm.yml');
-        rmdir(__DIR__ . '/convert');
+    public function tearDown()
+    {
+        @unlink(__DIR__ . '/convert/User.dcm.yml');
+        @unlink(__DIR__ . '/convert/Profile.dcm.yml');
+        @rmdir(__DIR__ . '/convert');
     }
 }