You have done replacing Buffalo stock firmware with Debian, the last part is to adjust the hardware behavior to match the new operating system.
This work initially done by Sergej Wildemann for LinkStation Live V2 with my modification for LinkStation LS421DE for both Buffalo kernel and vanilla one.
What’s LSMONITOR jobs:
- Controlling LED according to the current state (booting, power off, etc).
- Monitor the temperature of HDDs and adjust the fan speed according.
- Monitor power off switch and initiate shutdown when power switch position is off.
Do the following commands on your LinkStation LS421DE. If you have installed previous lsmonitor init script just remove it first:
$ update-rc.d lsmonitor stop
$ update-rc.d lsmonitor remove
Get init script and extract:
$ wget https://github.com/tohenk/linkstation-mod/raw/master/lsmonitor/lsmonitor-unified.tar.gz
$ tar -xvf lsmonitor-unified.tar.gz -C /
Install required packages:
$ apt-get install smartmontools hdparm evtest
Enable init script:
$ update-rc.d lsboot defaults
$ update-rc.d lsmonitor defaults
Restart LinkStation LS421DE to take effect.