diff --git a/include/Image.h b/include/Image.h
index 63feb4f996..639a5533e2 100644
--- a/include/Image.h
+++ b/include/Image.h
@@ -204,8 +204,11 @@ public:
      *    - Several DATABLOCK images can be mounted, they will be set to
      *      prefix + (d + index) :   hdd, hde, hdf...
      * @param disk attribute for the VM template
+     * @param index number of datablock images used by the same VM. Will be
+     *              automatically increased.
+     * @param img_type will be set to the used image's type
      */
-    int disk_attribute(VectorAttribute * disk, int * index);
+    int disk_attribute(VectorAttribute * disk, int* index, ImageType& img_type);
 
     // ------------------------------------------------------------------------
     // Template
diff --git a/include/ImagePool.h b/include/ImagePool.h
index 968188178d..73289a1f36 100644
--- a/include/ImagePool.h
+++ b/include/ImagePool.h
@@ -168,9 +168,13 @@ public:
     /**
      *  Generates a DISK attribute for VM templates using the Image metadata
      *    @param disk the disk to be generated
+     *    @param index number of datablock images used by the same VM. Will be
+     *                 automatically increased.
+     *    @param img_type will be set to the used image's type
      *    @return 0 on success, -1 error, -2 not using the pool
      */
-    int disk_attribute(VectorAttribute * disk, int * index);
+    int disk_attribute(VectorAttribute * disk, int* index,
+                        Image::ImageType& img_type);
 
     /**
      *  Generates an Authorization token for the DISK attribute
diff --git a/src/image/Image.cc b/src/image/Image.cc
index d59f00f7e8..31f6f80438 100644
--- a/src/image/Image.cc
+++ b/src/image/Image.cc
@@ -546,7 +546,9 @@ void Image::release_image()
 /* ------------------------------------------------------------------------ */
 /* ------------------------------------------------------------------------ */
 
-int Image::disk_attribute(VectorAttribute * disk, int * index)
+int Image::disk_attribute(  VectorAttribute * disk,
+                            int * index,
+                            ImageType& img_type)
 {
     string  overwrite;
     string  saveas;
@@ -554,6 +556,8 @@ int Image::disk_attribute(VectorAttribute * disk, int * index)
 
     ostringstream  iid;
 
+    img_type = type;
+
     overwrite = disk->vector_value("OVERWRITE");
     saveas    = disk->vector_value("SAVE_AS");
     bus       = disk->vector_value("BUS");
diff --git a/src/image/ImagePool.cc b/src/image/ImagePool.cc
index 6982dda21b..09854fedf9 100644
--- a/src/image/ImagePool.cc
+++ b/src/image/ImagePool.cc
@@ -165,7 +165,9 @@ int ImagePool::dump(ostringstream& oss, const string& where)
 /* -------------------------------------------------------------------------- */
 /* -------------------------------------------------------------------------- */
 
-int ImagePool::disk_attribute(VectorAttribute * disk, int * index)
+int ImagePool::disk_attribute(  VectorAttribute * disk,
+                                int * index,
+                                Image::ImageType& img_type)
 {
     string  source;
     Image * img = 0;
@@ -202,7 +204,7 @@ int ImagePool::disk_attribute(VectorAttribute * disk, int * index)
         return -1;
     }
 
-    int rc = img->disk_attribute(disk,index);
+    int rc = img->disk_attribute(disk,index, img_type);
 
     img->unlock();
 
diff --git a/src/vm/VirtualMachine.cc b/src/vm/VirtualMachine.cc
index feca468b3f..bbde093e17 100644
--- a/src/vm/VirtualMachine.cc
+++ b/src/vm/VirtualMachine.cc
@@ -388,7 +388,6 @@ error_leases:
     return -1;
 
 error_images:
-    NebulaLog::log("ONE",Log::ERROR, "Could not get disk image for VM");
     goto error_common;
 
 error_context:
@@ -826,6 +825,10 @@ int VirtualMachine::get_disk_images()
     ImagePool *           ipool;
     VectorAttribute *     disk;
 
+    int     n_os = 0;
+    int     n_cd = 0;
+    string  type;
+
     Nebula& nd = Nebula::instance();
     ipool      = nd.get_ipool();
 
@@ -841,41 +844,86 @@ int VirtualMachine::get_disk_images()
             continue;
         }
 
-        rc = ipool->disk_attribute(disk, &index);
+        Image::ImageType img_type;
+        rc = ipool->disk_attribute(disk, &index, img_type);
 
-        if (rc == -1) // 0 OK, -1 ERROR
+        switch(rc)
         {
-            return -1;
-        }
-
-        // -2 not using the Image pool, and type is swap
-        if ( rc == -2 )
-        {
-            string type = disk->vector_value("TYPE");
-
-            transform (type.begin(), type.end(), type.begin(),
-                       (int(*)(int))toupper);
-
-            if( type == "SWAP" )
-            {
-                string target = disk->vector_value("TARGET");
-
-                if ( target.empty() )
+            case 0: // OK
+                switch(img_type)
                 {
-                    Nebula&       nd = Nebula::instance();
-                    string        dev_prefix;
-
-                    nd.get_configuration_attribute("DEFAULT_DEVICE_PREFIX",
-                                                    dev_prefix);
-                    dev_prefix += "d";
-
-                    disk->replace("TARGET", dev_prefix);
+                    case Image::OS:
+                        n_os++;
+                        break;
+                    case Image::CDROM:
+                        n_cd++;
+                        break;
+                    default:
+                        break;
                 }
-            }
+
+                if( n_os > 1 )  // Max. number of OS images is 1
+                {
+                    goto error_max_os;
+                }
+
+                if( n_cd > 1 )  // Max. number of CDROM images is 1
+                {
+                    goto error_max_cd;
+                }
+
+                break;
+
+            case -2:  // not using the Image pool
+                type = disk->vector_value("TYPE");
+
+                transform (type.begin(), type.end(), type.begin(),
+                           (int(*)(int))toupper);
+
+                if( type == "SWAP" )
+                {
+                    string target = disk->vector_value("TARGET");
+
+                    if ( target.empty() )
+                    {
+                        Nebula&       nd = Nebula::instance();
+                        string        dev_prefix;
+
+                        nd.get_configuration_attribute("DEFAULT_DEVICE_PREFIX",
+                                                        dev_prefix);
+                        dev_prefix += "d";
+
+                        disk->replace("TARGET", dev_prefix);
+                    }
+                }
+
+                break;
+
+            case -1: // ERROR
+                goto error_image;
+                break;
         }
     }
 
     return 0;
+
+
+error_max_os:
+    NebulaLog::log("ONE",Log::ERROR,
+                    "VM can not use more than one OS image.");
+    goto error_common;
+
+error_max_cd:
+    NebulaLog::log("ONE",Log::ERROR,
+                    "VM can not use more than one CDROM image.");
+    goto error_common;
+
+error_image:
+    NebulaLog::log("ONE",Log::ERROR, "Could not get disk image for VM");
+
+error_common:
+    return -1;
+
 }
 
 /* -------------------------------------------------------------------------- */