I have seen a few messages about CRC errors, since then I did swap out one of the SAS to 4xSATA cables based on some advice when I posted this on a different platform, and so far it seems to be working reliably now. So I think that might have been my problem.

In order to make it so that I could actually keep working in the short-term, (because I don’t have a week to wait for a Parity sync…) I have removed the Parity drive from the array so that I can move data on without having to wait for the Parity sync to finish. My intention is to copy all of the data onto the array and then once All the data is in add the parity drive back in, let it do a Parity sync, and then once that sync is done then wipe and add those 20 terabyte drives (The ones that currently have data on them) to the array.

Does this seem like a worthwhile plan?

Are there any software methods I can use to try to narrow that down? I don’t exactly have a ton of spare hardware to just swap in to test it 😅

I do have an HBA. it is a LSI 9300-16I. And I’ve got a fan zip tied to it so that the heat sink has proper cooling. I’ve got these SAS to sata cables running to the backplane of the NAS bays. It converts each one of those SAS ports to 4x SATA plugs.

The case I’m using has a back plane where I connect the SATA data, and the molex power. It’s got one molex power per 4 drives. Currently both of those are off of a single cable running off the power supply. I’ll swap that to be a dedicated cable for each.