Here is a list of known issues and bugs with Debian on the QNAP TS-109:
- The installer fails to make the system bootable, especially on configurations with LVM and RAID. You can apply a workaround.
- qcontrol (the tool to control LEDs and beeper) doesn't work.
- On fanless QNAP systems (TS-109 and TS-109 II), fan errors are reported. There is a patch for this issue.
- Current versions of the Linux kernel fail to boot