I woke up this morning to 2 disks disabled and read errors on a bunch of others. Errors seem to have started around 3am. I am at a bit of a loss as to how to proceed. Any ideas what I should be trying first?

Help Please!!

tower-diagnostics-20251128-0835.zip

Edited November 28, 2025Nov 28 by mattekure

It's not logged as a controller issue. Are the disks powered by a splitter, or are they in a separate enclosure? In any case, reboot, then post new diags after array start to see the damage.

The disks are not powered by a splitter and not in a separate enclosure. They are powered by a standard corsair PSU SATA cable with 3 disks per cable. I have rebooted and taken diagnostics as soon as the array started.

Not sure if it matters or not, but the disks had been set to spin down after 15 mins. It seems likely most of the disks were spun down at the time.

tower-diagnostics-20251128-1022.zip

Edited November 28, 2025Nov 28 by mattekure

Emulated disk4 is mounting; assuming contents look correct, you can rebuild on top and rsync parity at the same time.

34 minutes ago, mattekure said:

but the disks had been set to spin down after 15 mins.

I assume this is not new, i.e., they have been spinning down/up before without issues?

Yes, its been set to spin down for a while now and this is the first time I've had issues.

How do I initiate the rebuild? and parity rsync? The data on the drive does look fine and I have an offline backup if I find any wrong files.

You can do it for both at the same time:

https://docs.unraid.net/unraid-os/using-unraid-to/manage-storage/array/replacing-disks-in-array/#re-enabling-a-disabled-disk-rebuilding-onto-itself

Ok, I have followed the instructions linked to bring the array down, de-selected the devices, start, stop and reselect the devices and start in maintenance mode. The instructions indicate that the rebuild is supposed to start, but nothing seems to be happening and I see no disk activity. There is a Sync button now that says it will start Parity-Sync, is that the button I have to click to kick off the rebuild and repair of both drives?

16 minutes ago, mattekure said:

start in maintenance mode

Maintenance mode is optional; if you use that, you need to click the sync button. You can also just stop and restart in normal mode so that the array will be online during the rebuild, but avoid heavy usage.

Thanks so much. I have kicked off the sync. I left it in maintenance mode as I dont need the array until its done.