I use the Disks application (preinstaled in Ubuntu 18.04) to configure standby timeout of my HDD disk. By using the Drive settings... -> Standby menu I've configured Standby Timeout to 15min. The disk goes into standby after 15min of idle state only if I disable S.M.A.R.T. monitoring by using the SMART Data & Self-Tests menu. By using the
sudo hdparm -y /dev/sdb command I can force the disk into standby regardless the SMART monitoring is turned on or off.
I want to have SMART monitoring and Standby timeout both enabled, but the features seem to collide with each other.
Is there any way to fix the problem without excess hacking?