Issue

Synology DiskStation 415+ NAS failed. Blue power button LED keeps blinking. Status LED is off. All 4 disk orange LEDs steady on (there are only 2 HDDs installed). Removing all hard drives doesn’t change anything. Replacing RAM doesn’t change anything either. All this indicated motherboard failure. Owner asked to recover data from hard drives.

Resolution

• Connect both hard drives to a PC.
• Boot PC from a Linux Mint (18.3) Live CD.
• Open Terminal and run:
  • sudo apt-get install mdadm
  • sudo sudo apt-get install lvm2 (in my case it was already installed)
  • sudo mdadm -Asf && vgchange -ay
• Wait few seconds and the RAID is mounted as a new volume.
• Browser the volume and copy required folders to an external USB drive.

December 2017
Synology DS 415+
Linux Mint 18.3