--- old/usr/src/uts/common/fs/zfs/metaslab.c	Mon Apr  7 00:45:25 2008
+++ new/usr/src/uts/common/fs/zfs/metaslab.c	Mon Apr  7 00:45:25 2008
@@ -843,9 +843,12 @@
 			}
 
 			DVA_SET_VDEV(&dva[d], vd->vdev_id);
-			DVA_SET_OFFSET(&dva[d], offset);
-			DVA_SET_GANG(&dva[d], 0);
+			if (vd->vdev_ops->vdev_op_grid != NULL)
+				DVA_SET_GRID(&dva[d],
+				    vd->vdev_ops->vdev_op_grid(vd);
 			DVA_SET_ASIZE(&dva[d], asize);
+			DVA_SET_GANG(&dva[d], 0);
+			DVA_SET_OFFSET(&dva[d], offset);
 
 			return (0);
 		}