While investigating why my hard drive load cycle count was increasing, I observed my APM level gets reset each time I come out of Suspend on my Debian Jessie laptop running MATE:
$ sudo smartctl --get=apm /dev/sda ... APM feature is: Disabled $ sudo hdparm -I /dev/sda | grep level Advanced power management level: disabled $ sudo hdparm -B /dev/sda /dev/sda: APM_level = off
After putting the laptop into Suspend and then taking it out of Suspend, I have the following:
$ sudo hdparm -I /dev/sda | grep level Advanced power management level: 128 $ sudo smartctl --get=apm /dev/sda ... APM level is: 128 (minimum power consumption without standby) $ sudo hdparm -B /dev/sda /dev/sda: APM_level = 128
I tried enabling the APM options in
/etc/hdparm.conf, but it didn't seem to help:
... # -B apm setting #apm = 255 apm = 255 # -B apm setting when on battery #apm_battery = 127 apm_battery = 255 ...
$ sudo /etc/init.d/hdparm restart
After putting the hard drive into Suspend and bringing it back out, I noticed the APM level is back to 128.