I want to learn more and as goal, I want to install a Linux on my NAS (QNAP TS-451)
@Tambry: Welcome to TinyCore!
QNAP already has a custom linux image running on it, and yes, it's full of bloat and restrictions galore where third party repositories are required just to get it to operate a little more Linux'y.
WARNING: Modifying the firmware is a one-shot deal! Be sure you have ALL of the necessary VIDEO, USB, STORAGE and NETWORK drivers before you begin; once you've overwritten the internal 512MB'ish flash there's no turning back!
I have the x31 series units here (ARM based) and not the x51 (Celeron based) so I cannot walk you through the process directly, but can give you a few pointers to make the transition easier. Bare in mind, the QNAP systems are usually not your standard run of the mill motherboard with BIOS that's accessible and programmable by the end user which will boot by CD/DVD or USB (or not that I was aware of...) That would make your task too easy!
Based on your details,
here is your system from inside.
IF the above matches your system (Dual Core Celeron) we'll need to dig a little deeper and determine the NETWORK hardware as Power-Up didn't mention it and I cannot zoom in close enough to tell what chipset it runs off of. I'm assuming it uses the same chips as
it's big brother, the 451+ (Intel WGI210AT 1GBe chips)
If your standard Linux kernel and/or third party drivers are readily available, start collecting them before making any attempt at installing Linux of ANY flavor permanently. You'll also want to create a DD image of the flash as it stands right now "just in case."
Before considering replacing your existing Linux kernel, I'm going to recommend USING the existing setup to get rid of the bloat; this way you can always "Factory Reset" if you get yourself into trouble. The first thing you need to do, however, is to offload any and all files on the device that you want to keep -- they may not survive the trip!
Once your system is good to experiment with, search G00gle for QNAP third party repositories such as MyQNAP if they still exist. You'll find instructions on how to use the APPS console to install the repository. Once installed, search that repo for a package called ENTware. This is vital at this stage as it'll give you access to software extensions that QNAP otherwise doesn't make available to you - which is "most everything else" found in a Linux environment.
Once you've located and installed ENTware, go into your Control Panel > Telnet/SSH and ENABLE SSH if you haven't already. SSH is going to become your new best friend since you'll be getting rid of QTS in the end, which is their web-based control system. If you prefer to connect a keyboard and HDMI monitor, you can also (likely) do all of this from the QNAP itself instead of SSH, but I don't know the limitations of the x51 series of what you see on the screen; whether it's the shell or their version of a desktop. The shell is preferred.
Once ENTware is installed, go into the shell and install pciutils and usbutils which is going to help us determine your exact hardware setup
ipkg update
ipkg install pciutils
ipkg install usbutils
NOTE: I have ENTware installed on two different ARM platforms (ARM6 and ARM7) and the app is "ipkg" on one and "opkg" on the other... if the above complains about not being able to find ipkg... switch to opkg instead.
Afterward, create a number of text files to attach here on the forum
dmesg > /mnt/Public/dmesg.txt
uname -a > /mnt/Public/uname.txt
pciutils > /mnt/Public/pciutils.txt
usbutils > /mnt/Public/usbutils.txt
NOTE: This assumes you still have the default Public share set up. Change "Public" to one of your share folder names if you do not.
Get this far and return here with your experiences and attach your files. You may have to attach dmesg.txt separately depending on its size.
@Rich: I have to go "under the knife" (so to speak) in a few hours and may not be back online for a bit. Head over to the links I posted above if you would, please, and check to see if the chipsets Power-Up did list are in fact kernel supported. I
believe the major differences between the 451 and 451+ were the enclosures themselves, the CPU (Dual vs. Quad) and I THINK the PSU, but I cannot be certain as that was a decade'ish ago and like when you're out fishing... something that small usually gets thrown back, and with such a high price tag (at the time)... I was happy to do just that; we purchased a half dozen or so Atom boards and built our own devices for roughly the same price as
one of theirs and ended up using
Webmin as a really easy control panel that fit the bill perfectly for what the devices were intended - almost completely ready to run out of the box
Good luck!