Given the innate capabilities of the current Raspberry Pi platform, I suggest using it as intended - For example, as a cheap media server for data you don't care about losing or getting corrupted. For that use case, it is absolutely great. I run a time machine vault on a RPi 4 with the three kid accounts on it so I can keep their laptops 100% off my private network. I back them up periodically but I would not cry a tear if I lost that data.
TrueNAS / FreeNAS / SCALE / whatever is targeting a very different market. First and foremost, to me, the hardware requirements and the complexities involved with installing TrueNAS are justified by ZFS and its many data-integrity benefits. One layer down are all sorts of protocols, permissions structures, etc. that allow for a incredibly flexible installation. All sorts of use cases can be covered very reliably, especially if you stick to recommended hardware platforms / add-ons.
Once you venture out of the protective forest of Intel and AMD-based options and decide to start planting new saplings in ARM-land, etc. you are literally on your own. Why further increase your chances of pool destruction by stacking the odds against yourself? Crummy HBAs, insufficient or non-ECC RAM, all those factors basically reduce the achievement of running TrueNAS on a Rpi to a mere curiosity: no doubt, a technical achievement, perhaps a stepping stone to something greater in the future, but certainly not a good solution for anything other than scratching an intellectual itch.
OMV makes a lot of sense on limited hardware platforms because its scope is far more limited than what TrueNAS tries to be. Ditto for bcache, Netatalk, and so on. RPi can be tailored to do all sorts of limited tasks really well and do so at a price point that TrueNAS may not be able to touch. However, once you get into server-land and you expect the flexibility, reliability, etc. of a production server, RPi has little to no role with its current capabilities, no matter how much lipstick you apply.
I'd love to see ARM come to the SOHO market, especially for storage-oriented solutions like the
SuperMicro X10SDV-2C-7TP4F, which offer oodles of high-quality storage interfaces, a fast NIC, a couple of PCIe lanes for future expansion, etc. A ARM solution could offer even better performance at fewer Watts and with less heat. However, there is the pesky chicken/egg problem with hardware that even AMD-based solutions have to contend with. (Note the relative dearth of AMD-based motherboards at Supermicro and elsewhere even though AMD is nominally compatible with Intel)
Custom solutions for cloud providers are a bit out of reach for the most of us.
Anyone have a couple of million of USD burning a hole in their pocket and a high appetite for risk? Then put together a kick-bum team of hardware developers, bring out something like a
SuperMicro X10SDV-2C-7TP4F that can use ECC RAM, offers 2+ PCIe lanes, etc and then pay the big $$$ to the likes of iXSystems to port TrueNAS to that platform. It's not going to be easy and you haven't even started to address the fundamental challenges of consumer acceptance, awareness, etc. Maybe the folk at Kickstarter will be willing to burn their excess cash this way?
I prefer giving excess money to the FreeNAS project, at least there I have a much higher possibility of benefitting those whose lofty shoulders I get to stand on.
