Cactus42

So does that mean if I run the array without a parity drive (I mean for testing - I can back up the important contents elsewhere while I do so) i can see if i still get errors but it won't disable the drive? I want to see if it's something to do with my data, the way it's being synced etc as I've pretty much ruled out hardware.

OK, I was under the impression it was error count based as that's the point that this one is being disabled, but that doesn't explain why Unraid is disabling good drives only when on a specific chosen point in the array. When not in the array they all pass preclear, they have been tested in other machines. This happens on all 8 SAS connectors which work fine for other drives, same with SATA power connectors. Does Unraid get upset at other reasons for a write fail even if a drive is fine? like bad data on a good drive being copied (not that I've done that while this has been going on). Could a bad parity write/update cause this (Parity was fine and tested every month until the first failure showed up)?

I've now tested with another known good drive with the same result. All 3 drives have been tested again under Windows and Linux with no issues and as above not showing as a disk problem. It's always disk 3 regardless of which physical SAS connection or SATA power connection is used. Currently it's looking like I may have to move to one of the above alternatives and lose the array functionality which isn't something I want to do.

I have a similar issue that leads to read/write errors only on a specific drive point in unraid which then gets disabled (Like you I have replaced PSU, SAS cables, removed SATA extenders and checked and reseated HBA controller) and thinking there may be a bug involved as the former physical drive and the current one don't show the failure as drive related and work/test fine in other non-unraid machines, as does the HBA controller

I have a strange issue (to me...) Drive 3 repeatedly disables based on error count. It is only ever drive 3. All array drives (except Parity) are SAS drives running off a 2 port LSI SAS controller, using the miniSAS 8087 to 4x SAS/SATA power combined connector (SATA power plugs into the back) Steps taken so far: Replaced the drive with a known good unit Changed power connection for SAS drive Changed SAS connection for SAS drive Changed port on controller for the 8087 end Changed cable to SAS drives from controller (bought brand new one) Replaced power supply for system (was using a Gamemax now using Corsair RM Modular - all drives are directly connected with no splitters) Even with all those changes it's still only ever drive 3 that disables. I'm stumped and going to resort moving the emulated content to the other drives and cutting down to 4 array drives in the mean time. Diagnostic data added Thanks serenity-diagnostics-20250211-1407.zip