Rock64 NAS project

[stuartiannaylor]

Don't do RAID over USB3 hub, it will break, and very baddly Use only proven to work SATA-to-USB adapter, that has UASP support, as this gives a good performance.

There's a very good and long thread from tkaiser on Armbian forum where he describes SATA bridges, NAS solutions, and Rock64 performance numbers and he has good explanations what setups will work correctly.

I have to disagree and not because it will not break, as it prob will but for the lack of reasons to why it should.

Much is to do with power & connectors and with the kernel we have and some quirks on cheap silicon.
UASP is transparent across a hub so all a hub does is increase cable length and connector count if its a decent hub with a good chip.
Many of the problems are how host port stacks are implemented on the motherboard and not all are the same.
Kernel 4.4 is the current image 4.6 = USB 3.1 prob really with images we should already be backporting kernel 4.9 as we have hardware that is further forward than the 4.4 mainline kernel we are currently employing.

tkaiser rightly highlights some bad chips and implementations that also have been used on some SoCs and are just plain bad and this is where I disagree as what is the good?
Are people suggesting that every RAID multibay enclosure / adapter on the market is bad from a whole range of big name manufacturers?

What is the good and if bad why exactly as "it will break baddly" doesn't really convey enough infomation.
This is an avenue to explore and if we do get some answers to maybe latency is a factor then maybe alternatives such as SnapRaid, SyncThing or completely lateral implementations of distributed file stores.

If its cabling and power what can we do to improve this, which chips should you dodge, if kernel can we backport, blacklist or remove from blacklist.

We need that info and I will be one trying certain implementations and posting findings as we are getting to a stage where some form of combination should work.