I don't know of any graceful method for a KDM restart. Leaving KDM running even if it's no use to log in is fine, certainly better than killing the upgrade half way through and users are prompted to restart the machine after the upgrade is complete.
I don't know of any graceful method for a KDM restart. Leaving KDM running even if it's no use to log in is fine, certainly better than killing the upgrade half way through and users are prompted to restart the machine after the upgrade is complete.