The current documentation of overlayfs states the following: Multiple lower layers --------------------- Multiple lower layers can now be given using the the colon (":") as a separator character between the directory names. For example: mount -t overlay overlay -olowerdir=/lower1:/lower2:/lower3 /merged As the example shows, "upperdir=" and "workdir=" may be omitted. In that case the overlay will be read-only. Consider the case /lower1/A and /lower2/A exist. What is part of the api - that it is undefined or that one takes presedence over the other? It would be nice to have this clarified in the documentation. Thanks, Fabian -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html