http://forum.openvz.org/index.php?t=tree&th=412&mid=2429&&rev=&reveal=

--- ./fs/isofs/inode.c.isofs	2006-03-20 18:29:32.000000000 +0300
+++ ./fs/isofs/inode.c	2006-04-04 15:39:52.000000000 +0400
@@ -1459,7 +1459,7 @@ static struct file_system_type iso9660_f
 	.name		= "iso9660",
 	.get_sb		= isofs_get_sb,
 	.kill_sb	= kill_block_super,
-	.fs_flags	= FS_REQUIRES_DEV,
+	.fs_flags	= FS_REQUIRES_DEV | FS_VIRTUALIZED,
 };
 
 static int __init init_iso9660_fs(void)