Currently there is no way to schedule S.M.A.R.T. tests - running these tests taxes the hard drives and it is not recommended to be run frequently. As with some other advanced features of DSM 3.0, S.M.A.R.T. testing is meant to be used by system admins as it is not likely most end users would be able to accurately interpret its results.S.M.A.R.T. testing is not a deterrent to bit rot and is not meant to be run frequently enough to require scheduling. As always, the only way to prevent data loss through bit rot/fire/flood/theft/etc is to have off site backups.