SO. Many years ago I RAIDed my PC. First with (ugg I hate to say it) Port Multiplier(s).
Then a hardware RAID card
NOW.
ZFS. Still need a SAS-SATA Card. I have had this issue before, 3rd HDD "degrades". Replace HDD, scrub, attempt to repair damaged files.
Now I have a 8x PCIe SAS-SATA Card. 2 Ports. I have a Micro Gigabyte Motherboard, so this SAS-Sata card sits in the x16 (graphics) slot. To attempt to find and fix this degrade problem I have done the following
Swapped Cables in SAS-Sata Ports, scrub, swapped degraded hdd, scrub.
Plug HDD to MB and physically run HDD diagnostics. All pass
Swapped Power Cables. Swapped Power Supply PORTS.
Swapped SAS-Sata Cables. Purchased new cables and used them
Purchased new different model SAS-Sata PCIe Card, Swapped Card
Re-swapped SAS-Sata Cables & Power Cables
I've even purchased 8 new HDD's and copied (or moved) data over.
Problem always appears weeks to months later, as the 2nd Port (Port 1) on the SAS-Sata card and ALWAYS the 3rd HDD is Degraded.
I've lost my Dads (RIP) 90th Birthday Video as it was damaged and unrepairable. I have lost countless other files.
Can someone with Linux OS, and ZFS or zpool, please offer me an explanation on what is going on.
TIA