Weirdest problem: data disks invisible to TrueNAS until I boot into Ubuntu once

[luqasn]

Hi folks,

I have the weirdest problem that I've been scratching my head over for the past two days.

I moved my boot ssd and the two 16TB disks that make up my ZFS pool from a supermicro-based build to a more power friendly EliteDesk 800 G3 build.
I could boot into TrueNAS just fine, but the two data disks were nowhere to be seen, even though they appear in the machine's BIOS.
By "nowhere to be seen" I mean fdisk -l would not show them neither would blkid. dmesg only stated SATA link down for the affected ports.

I tried every BIOS setting permutation I could think of, rebooting constantly - nothing.
Then I created a Ubuntu USB stick to see if the OS was the issue. Booted into Ubuntu - no problem at all, disks show up perfectly in fdisk.
Incredulous I reboot into TrueNAS - now they show up there too!

So I now have the setup working nice, but in a very brittle state: if I simply reboot, the disks stay visible to TrueNAS, but if I shut down and start up again (without removing power), I need to go through the whole "boot ubuntu from usb" first.

I am totally at a loss here, in all of my years of computing I have not experienced such inexplainable weirdness.
Does anyone of you have an idea what could be going on? I'd be very grateful!

Some details, let me know any more info you need:

EliteDesk BIOS is latest: 02.46 Rev.A
Disks are two Toshiba MG08ACA16TE.
TrueNAS is TrueNAS-SCALE-22.12.3.1
Ubuntu is version 23.04

 

[Arwen]

Sounds like the drives are powered down until Ubuntu powers them up;

SATA - Wikipedia

en.wikipedia.org

Pin 3 was normally 3.3v but became power disable for some newer spinning disk drives.

Don't know why Ubuntu would change that. Though it is possible your EliteDesk 800 G3 computer has that feature built in. Then Ubuntu is programed to use it.


Easy enough to test the fix, get a different power cable that does not pass through pin 3. Or block off pin 3.

 

[winnielinnie]

Or block off pin 3.

Just want to share some personal experience.

Blocking off pins 1 through 3 will yield the same result, and it's much easier to do. Rather than dealing with an ultra narrow piece of (Kapton) tape, you have a wider piece to work with, which will also stick better. (It's also easier to "place" the tape to only cover those three pins, rather than trying to use ultra precision to overlay a very narrow piece to only cover pin 3 precisely.)

 

[luqasn]

Thanks a lot to both of you for your help!
Unfortunately, the EliteDesk 800 G3 does not provide 3.3V on its SATA power connectors, so this can’t be the issue.

I looked into it a bit more and there seems to be another power feature on pin 11 called SSU and also PUIS (https://en.m.wikipedia.org/wiki/Spin-up#Staggered_spin-up).

But it seems to me that at least the disks should be visible in the device tree so one can send commands to it.
So no idea if I am on the right path here.

hdparm -I didn’t reveal any information about PUIS on my drives.