(Update 2020-12-31) I wrote up the installation procedure on a project-page. Have a look if you are interested.
(Update 2021-08-29) I was notified that OpenWrt might lead to suboptimal NAS performance on some models of the Medion NAS. See comments section for details.
We have an old Medion NAS server from the German supermarket chain ALDI. There is no model-number on the device or anything, but from what I could reverse engineer it is most likely the model P89635 from the year 2012.
Old software = unusable device
The server served us well for some years but after only 3-4 years it started to fail on us. The issue was not the hardware, but the software: The Software that is installed on these NAS systems is an old version of some Zyxel Linux OS which only supports the Samba 1.0 protocol which was deactivated in recent versions of Windows and Linux. This meant that the drive could not be used from Windows anymore and only with tricks on Linux. Pretty inconvenient.
Normally one would fix this issue with a software update, but there are none. No upgrades. The software was stuck on version 1.01a (if I remember correctly) with the outdated Samba server. So I had to find another way to do patch the Samba server.
OpenWrt to the rescue
We ended up replacing the NAS with a custom-build NAS server, but the hardware was still lying in one of my cabinets. So, with COVID-19 raging and not much else to do, I checked whether it was possible to breath some new life into the old device. I found that OpenWrt references install instructions for the Medion model md86587 (Note: the instructions on that page refer to these and these instructions, specifically. Do not use the ones from the official page – they are outdated. This is accurate advice for 2020-12-19).
All in all, installing OpenWrt amounted to the most complicated Linux install that I ever did. It required disassembling the NAS, building a custom serial interface for interacting with the device’s bootloader, and setting up tools I never used before.
Even though the process way quite involved, it finished pretty smoothly. OpenWrt now is installed on the system, I was able to install and configure Samba, and now it can assume its old role again – maybe a nice little Christmas present?
I captured extensive documentation of my process. I intend to put it in some form of document for later reference. No promises, but if I do so, I will post it on this page.