My OMV6 is set up on a Lenovo laptop (Intel i7 based). The system is installed on NVMe drive. 2 external WD Red Plus hard drives are connected through SATA interfaces, and one of them is from the DVD drive. Both of them are set to APM level 254 (max performance without standby) through OMV6's GUI. However, the APM level setting of the hard drive connected DVD SATA connector seems to have no effect every time after reset. It will go to standby after one minute of use. If I set APM level to a different level such as 192 (intermediate power usage without standby), it will not go back to standby until the next reset. The other hard drive connected to the main SATA interface does not have this problem (never going to standby). I tried swapping hard drives and found the issue is always associated with the drive on DVD SATA interface. I thought I could solve this problem by setting APM level every time in a power-up script. Unfortunately, it didn't work. Here are the two commands I have tried and none of them works:
hdparm -B 254 /dev/sdc
smartctl --set=apm,254 /dev/sdc
These commands did set APM level correctly but that hard drive still went to standby regardless. If I change APM level through OMV6 GUI, that hard drive will not be switched to standby (until next reset). I wonder what command OMV6 used. Thanks a lot for any help.