[Not possible] SSD Boot from Quad sata Hat

Hello radxa community,

I’ve recently bought the Quad sata Pi hat, and I love it!
I’m only using 2 hard drives though, and I was thinking about installing and booting my pi off an ssd.

So I had 2 ideas:

  1. Try to use an ssd inside the Quad sata Pi hat, although I don’t know how this would affect speed.
    or
  2. Remove the dual usb connector, and since I’m only using 2 hard drives I can work with only 1 usb 3.0 between the pi and sata hat, and use the other 3.0 port for my ssd. But here I don’t know which USB corresponds to which sata port:
    Top usb for sata1 && sata2, Bottom for sata3 && sata4?
    or:
    Top usb for sata1 && sata3, Bottom for sata2 && sata4?

Another question, if option 1 were to work, would it be better for speed to keep the hard drives on a single usb connection (eg. top usb - sata1 && 2) and keep the ssd on sata 3 or 4, or would there be another way?

Which option would you think is better?

Thank you.

Edit, I haven’t found out with sata ports correspond to which usb, but I know that it’s not possible to boot from and ssd thats on the sata hat.

Oh that’s a pity - When I reached out to the guys via twitter, they raised no concerns regarding USB booting. So I’ll probably be unable to use the HAT

20

The thing is the sata hat software gets initialized only after booting, therefore an ssd connected to the sata hat cannot be seen, because the system needs to boot first.

I tried ones to boot from SSD by using the gpio-poweroff overlay to set the sata hat reset pin (GPIO 25 or 26, depending in with slot the boot disk is) high/low during boot and modified the hat’s python script in a way that it doesn’t overwrite the pin state. I got to a point that it was showing the “Welcome to Rasbian” messages, but after that it was incredible slow and almost doing nothing. Maybe it had something to do with this: https://www.raspberrypi.org/forums/viewtopic.php?t=245931

I gave up on it at the moment, but think it could be possible this way. If you look into the sata hat script, it only sets these pins high to mount the disks + a diff before and after to recognize with disks are added by the hat. The diff is only used to display the disk info, but isn’t needed to use the disks.

IMHO this is an important pending question!
I believe that for experts (@jim) it should not be too difficult to tell how the
GPIO pins can be manipulated early in the beginning so that the disks on the sata
hat get powered early and therefore can hold the system to be booted.

I agree.

I’m booting of an ssd (usb2.0 port) and using the microSD card as a backup.

It sucks even more because I’m only using only 2 HDD’s on the quad sata hat, basically rendering one of my 3.0 ports useless.

Well not fully useless, because I’m guessing if both hdd’s ran from the same USB3.0, speeds would be halved (from 110Mb/s to 55ish last time I tried using a 3.0 male to male cable just to connect one of the ports from the sata hat to the pi), but I think I would be willing to make that sacrifice just to have a faster filesystem. The problem here was that my sata->usb3.0 adapter’s chipset apparently doesn’t work on the Pi so it only works on USB2.0 speeds even though it works at 3.0 on both my laptop and pc. I’ve just dropped the case after this…

I’ve also tried booting off of the usb-c port but on the RPi4b it only has the USB 2.0 spec.

My hope is that at least one of the following 3 things happen:

  1. I save enough money to buy an actual server. (less likely :c )

  2. A new RPi comes out with 4 USB3.0 ports.

  3. The SataHat team figures out a solution how to boot from the sata hat.

I’m rooting for #3 but don’t tell anyone, it’s a secret.

About 1st - it’s not that costly as you think (look for some motherboard with embedded processor). The problem is electric bill in this case.

Also about 3rd, what the problem? Have you tried

Well money is not the only problem. If I ever switch homes, I’ll have to make sure to have a dedicated server room like linus. I don’t want to hear my server’s noise all day.

Also, the USB boot is working. It’s just that it’s running on an USB2.0 port, reducing my speeds greatly. The Quad sata hat uses both my 3.0 ports, even though I’m only using 2 HDD’s.

You wrote “I’m rooting for #3 but don’t tell anyone, it’s a secret.” but unfortunately
I can not understand it. Could you please enlighten me?

Thanks for pointing to that article from Tom’s hardware which also links to a similar
text from the foundation

However, point 3 from @pimpek agreeing that booting directly from the sata hat is a legitimate
request at the manufacturers of these hats and this problem does not get solved by booting
from an usb disk not attached to the hat.

BTW: I do not understand why the power of the SATA-disks gets switched on/off on the hat,
because switching off the drive motors would be possible by hdparm commands…
This IMHO was additional cost without any real use!

What I meant is I’m hoping that #3 will happen.

That “the SataHat team figures out a solution how to boot from the sata hat.”

Theoretically you could hardwire the GPIO pins that pilot the disks to 3V3. In the code change the GPIO config to INPUT instead of OUTPUT.
Just an idea, haven’t tested this.

Unfortunately I am nowhere near in having the experience to do this.

@pimpek:
It is a shame that Seedstudio does not at all care for their paying customers.
Maybe some lucky day the truth about the non existing customer care of Seedstudio gets known and a competitor with decent supports takes over…