Here is a list of known issues and bugs with Debian on QNAP TS-41x/TS-42x:
- On QNAP devices with 1 GB of RAM (i.e. TS-420U, TS-421 and TS-421U), the
installer fails because of a kernel issue. Messages in
BUG: Bad rss-counter stateand
Unhandled fault: external abort on linefetch. You have two options: 1) stay with Debian jessie, or 2) set the RAM size to 768 MB.