It's a crying shame that DKMS is so horribly broken on RHEL/CentOS/SL. Nothing like having it blithely make weak-updates symlinks to the ZFS and SPL modules that were compiled for your oldest still-installed kernel, only for those symlinks to end up pointing nowhere after that old kernel gets deleted. Oops! Your zpools now won't import until you clean up the mess. Been there, done that too many times.