diff --git a/datatypes_conf.xml.sample b/datatypes_conf.xml.sample
index 0e83c7e4d7c..bc5ec592c92 100644
--- a/datatypes_conf.xml.sample
+++ b/datatypes_conf.xml.sample
@@ -33,7 +33,7 @@
         </datatype>
         <datatype extension="customtrack" type="galaxy.datatypes.interval:CustomTrack"/>
         <datatype extension="csfasta" type="galaxy.datatypes.sequence:csFasta" display_in_upload="true"/>
-        <datatype extension="data" type="galaxy.datatypes.data:Data" mimetype="application/octet-stream"/>
+        <datatype extension="data" type="galaxy.datatypes.data:Data" mimetype="application/octet-stream" max_optional_metadata_filesize="1048576" />
         <datatype extension="fasta" type="galaxy.datatypes.sequence:Fasta" display_in_upload="true">
             <converter file="fasta_to_tabular_converter.xml" target_datatype="tabular"/>
         </datatype>
diff --git a/lib/galaxy/datatypes/data.py b/lib/galaxy/datatypes/data.py
index f799e672019..8b917806012 100644
--- a/lib/galaxy/datatypes/data.py
+++ b/lib/galaxy/datatypes/data.py
@@ -57,6 +57,8 @@ class Data( object ):
     composite_type = None
     composite_files = odict()
     primary_file_name = 'index'
+    #A per datatype setting (inherited): max file size (in bytes) for setting optional metadata
+    _max_optional_metadata_filesize = None
     
     def __init__(self, **kwd):
         """Initialize the datatype"""
@@ -116,6 +118,18 @@ class Data( object ):
             if not value:
                 return True
         return False
+    def set_max_optional_metadata_filesize( self, max_value ):
+        try:
+            max_value = int( max_value )
+        except:
+            return
+        self.__class__._max_optional_metadata_filesize = max_value
+    def get_max_optional_metadata_filesize( self ):
+        rval = self.__class__._max_optional_metadata_filesize
+        if rval is None:
+            return -1
+        return rval
+    max_optional_metadata_filesize = property( get_max_optional_metadata_filesize, set_max_optional_metadata_filesize )
     def set_peek( self, dataset, is_multi_byte=False ):
         """Set the peek and blurb text"""
         if not dataset.dataset.purged:
diff --git a/lib/galaxy/datatypes/qualityscore.py b/lib/galaxy/datatypes/qualityscore.py
index e51be3267b8..fadb9819e71 100644
--- a/lib/galaxy/datatypes/qualityscore.py
+++ b/lib/galaxy/datatypes/qualityscore.py
@@ -63,6 +63,13 @@ class QualityScoreSOLiD ( QualityScore ):
         except:
             pass
         return False
+    
+    def set_meta( self, dataset, **kwd ):
+        if self.max_optional_metadata_filesize >= 0 and dataset.get_size() > self.max_optional_metadata_filesize:
+            return
+        return QualityScore.set_meta( self, dataset, **kwd )
+
+
 
 class QualityScore454 ( QualityScore ):
     """
diff --git a/lib/galaxy/datatypes/registry.py b/lib/galaxy/datatypes/registry.py
index 338e4ac82a4..d0ef80752fb 100644
--- a/lib/galaxy/datatypes/registry.py
+++ b/lib/galaxy/datatypes/registry.py
@@ -64,6 +64,8 @@ class Registry( object ):
                             self.available_tracks.append( extension )
                         if display_in_upload:
                             self.upload_file_formats.append( extension )
+                        #max file size cut off for setting optional metadata
+                        self.datatypes_by_extension[extension].max_optional_metadata_filesize = elem.get( 'max_optional_metadata_filesize', None )
                         for converter in elem.findall( 'converter' ):
                             # Build the list of datatype converters which will later be loaded 
                             # into the calling app's toolbox.
diff --git a/lib/galaxy/datatypes/sequence.py b/lib/galaxy/datatypes/sequence.py
index 4d400318d62..522ca992319 100644
--- a/lib/galaxy/datatypes/sequence.py
+++ b/lib/galaxy/datatypes/sequence.py
@@ -148,6 +148,11 @@ class csFasta( Sequence ):
         except:
             pass
         return False
+    
+    def set_meta( self, dataset, **kwd ):
+        if self.max_optional_metadata_filesize >= 0 and dataset.get_size() > self.max_optional_metadata_filesize:
+            return
+        return Sequence.set_meta( self, dataset, **kwd )
 
 class Fastq ( Sequence ):
     """Class representing a generic FASTQ sequence"""
@@ -158,6 +163,8 @@ class Fastq ( Sequence ):
         Set the number of sequences and the number of data lines
         in dataset.
         """
+        if self.max_optional_metadata_filesize >= 0 and dataset.get_size() > self.max_optional_metadata_filesize:
+            return
         data_lines = 0
         sequences = 0
         seq_counter = 0     # blocks should be 4 lines long