Irreversible error when trying to upload image (too big) in a clone
What module are you using to clone a node? I recommend the Replicate module A workaround on your case now would be to alter the replicate functionality for the replication of image fields. You can clear the images field in code or copy the files yourself.

Here is an example for the replicate module to copy the images so your nodes don't use the same images because then you have unwanted behaviour on delete of one of the nodes (deletes the images):

/*
 * Implements hook_replicate_field_FIELD_TYPE().
 */
function replicate_custom_replicate_field_image(&amp;$replica, $entity_type, $field_name) {
   // List of affected fields.
   $fields_list = array(
     'field_xxxx' =&gt; 'contenttype1',
     'field_xxxxx' =&gt; 'contenttype2',
     'field_xxxxxx' =&gt; 'contenttype3',
     'field_xxxxxxx' =&gt; 'contenttype4',
     'field_xxxxxxxx' =&gt; 'contenttype5',
   );

   if (in_array($field_name,  array_keys($fields_list))) {
     // Fetch field instance info.
     $field_instance = field_info_instance($entity_type, $field_name,           $fields_list[$field_name]);
     // Build destination path.
     $destination_path = 'public://' . $field_instance['settings']['file_directory'];
     foreach ($replica-&gt;{$field_name} as $language =&gt; $field) {
       foreach ($field as $key =&gt; $value) {
         // Fid can't be empty.
         if (!empty($value['fid'])) {
           $new_file = file_copy((object) $value, $destination_path);
           $replica-&gt;{$field_name}[$language][$key] = (array) $new_file;
         }
       }
     }
   }
 }