Short version: Try running 'man mdadm.conf' If that doesn't produce a manual page please follow this link: http://man-wiki.net/index.php/5:mdadm.conf Long version: Rescue is probably the name of the last system to update the meta-data, either a rescue cd / system used for recovery or setup. The normal mdadm manual page should elaborate the use of these options: -U, --update=homehost --auto-update-homehost -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html