Until yesterday afternoon the HDD standby feature worked perfectly on my TrueNAS Scale 24.10.0.2. But suddenly it stopped going into standby and did not spin down the disks anymore.
The strange part is that I can put them into standby with hdparm -y /dev/sda and they stay in standby until used. Nevertheless I tried disabling all services and all apps and even unplugged the network cable. The disks refuse to go into standby. Reporting and iostat show now usage as well, so they should go into standby mode.
It also doesn’t work on the latest version 24.10.1
What could possibly cause such an issue?