In this tutorial we will install Synology DSM on a QNAP device (or any other hardware for that matter).

WARNING: I am uncertain about the legal implications of installing Synology DSM on non-Synology NAS devices. Therefore, I kindly request that you conduct thorough research on this matter prior to embarking on any related projects.
The QNAP TVS-h1688X, as well as other QNAP NAS models, are designed to boot automatically from an internal USB pen drive affixed to the motherboard. As a result, it is necessary to modify the startup procedure. It is also advisable to remove the USB pen drive from the motherboard to prevent accidental booting and initiation of the QNAP QTS installer.
To modify the startup procedure on a QNAP NAS, connect a monitor and keyboard to the device and access its BIOS (Press <DEL> during startup). This step is crucial as we'll be utilizing a USB pen drive to boot the "Automated Redpill Loader", a bootloader that enables Synology DSM to launch. Without this bootloader, the installation of Synology DSM would be impossible.

Important: Make sure the system is only able to boot from USB
Download the USB image from https://github.com/fbelavenuto/arpl/releases and unpack the zip file. At the time of writing the latest release is v1.1-beta2a.

Use Balena Etcher of whatever you want to use to "burn" the image to the USB drive.

Now insert the USB pen drive in the QNAP NAS and watch it boot. When the booting is done, you should see this screen:

You can invoke the installer by entering ./menu.sh
or by entering the IP address in your browser.
Now we are ready to configure the USB pen drive, nothing will be written to the drives you have installed in your QNAS yet. First step is to choose a Synology NAS model, we will choose the DS2422+ model. If you choose another model, the 4 LAN adapters will not function, so it's important to use this model.
Don't worry if you have more drives then the DS2422+ has, Synology DSM doesn't care 😃

Next step is to choose the build number. At the time of writing the latest version is DSM 7.1.1-42962 Update 5
so we will select 42962
.

Synology DSM will not boot if the system doesn't have the correct serial number and MAC address, luckily for us the bootloader will take care of this. Select "Choose a serial number" and then "Generate a random serial number".

That's it, now select "Build the loader", when this is done you can reboot your system.

When you reboot the system it will automatically boot to the installer of Synology DSM. It might take a while before you can access the URL, just give it a minute. If you have the monitor attached to your QNAP NAS then you will see a linux prompt that is not responsive, this is normal.
http://IP-OF-NAS:5000

The next steps are pretty straightforward, just install it like you would do with a real Synology NAS.



After this, DSM will restart and you can continue with the fresh installation of your new Synology NAS!
IMPORTANT: Please make sure your disable automatic updates and select "Notify me when DSM or package updates are available and I will install them manually".

If all went well, you should something similar to this:

Congratulations!
Known issues:
- Virtual Machine Manager (You won't be able to launch VM's on this NAS)