Hi guys, straight to the point: I purchased two used 12TB drives and wanted to replace my 6TB ones with those. I plugged in one of those, let it build parity alongside the other, but when it finished it said "Parity drive is disabled", I naively thought it was because it was executing an extended SMART test, so I cancelled it and followed some advice on this sub:

- First I precleared the drive, then let it rebuild parity again, same result.

- Stopped array, set parity to "no device", then started array in maintenance mode, stopped it again and reassigned the drive to parity, start and let it build parity, same result

- Checked psu and sata cables, nothing wrong with them

- Now I'm preclearing the other drive just to check if there's something wrong with them

I'm attaching the extended SMART test and diagnostics, if someone could help me I'd appreciate it.

anas-diagnostics-and-SMART.zip

Looks more like a power/connection issue; replace both cables and try again.

5 hours ago, JorgeB said:

Looks more like a power/connection issue; replace both cables and try again.

Hm... That's strange. Will do and report back.

Hi @JorgeB sorry to bother, ordered two new sata power cables, they still haven't arrived but I'll make sure to change them.

In the meantime, I checked both drives and tried to build parity on both of them, to no avail. One of them even threw some write errors:

Sep 24 17:10:53 ANAS kernel: ata2.00: error: { ABRT }
Sep 24 17:10:54 ANAS kernel: I/O error, dev sdc, sector 3904 op 0x1:(WRITE) flags 0x0 phys_seg 32 prio class 2
Sep 24 17:10:54 ANAS kernel: md: disk0 write error, sector=3840

Is it a bad drive? Maybe it's the PSU? I'm attaching again the diagnostics, can you tell me where do you look?

diagnostics.zip

Could be the PSU, it still looks like a power/connection issue.

@JorgeB Pinging you for this update.

New official cables arrived, did a parity-check and still the parity device is disabled... I really don't know what else to do, the return window for these drives is over and I can't use them. Do I have to do anything else in order to use these devices? Do I have to do a New Config for this?

There are 168 errors on the parity disk, is that something I should be worried about?

I'm attaching new diags :(

anas-diagnostics-20251005-1255.zip

I had a similar issue once — turned out the SATA cable was fine but the power connector was slightly loose. Try swapping cables or ports; Unraid can disable parity even from a momentary dropout.

_{Mini Militia App Lock}

Edited November 29, 2025Nov 29 by hillder

1 hour ago, hillder said:

I had a similar issue once — turned out the SATA cable was fine but the power connector was slightly loose. Try swapping cables or ports; Unraid can disable parity even from a momentary dropout.

Already did that, ordered some official cables for my PSU just in case the ones I was using were bad but nothing changed. It's also very strange that BOTH disks present this error, I reseated the cables several times already...

Forgot to mention I'm on 6.12.9, should I update? I don't wanna break more things to be honest...

23 hours ago, apool said:

did a parity-check and still the parity device is disabled..

If the drive was disabled, you need to resync parity, a check won't re-enable it.

Just now, JorgeB said:

If the drive was disabled, you need to resync parity, a check won't re-enable it.

Yes, it was a parity sync, my fault. Now doing another one with the other disk...

I don't see any read(write errors on the diags posted, do you know the time code it happended?

8 hours ago, JorgeB said:

I don't see any read(write errors on the diags posted, do you know the time code it happended?

Looks like it was on 3rd/4th, but the logs didn't pick it up. I'm finishing another parity-sync in around two hours, will post the results...

Same result with the other disk, it's very strange that only happens with these disks, isn't it?

I can't believe it, I think it also didn't pick up the messages for when the parity-sync finished, it was on 6th October at around 23:30, I went to sleep thinking it'd pick it up. Attaching the new diags just to be sure

What else can I do?

anas-diagnostics-20251007-0816.zip

Still no right errors logged, if you are not troubleshooting the mover, disable the mover logging to quiet that spam

Officially no clue as to why this is happening, parity sync finishes with 168 errors on both disks. In the logs it says: "ANAS kernel: md: disk0 write error, sector=23437500872" a bunch of times. Does that mean BOTH drives are officially dead?

I even changed SATA data cables, now I truly ran out of options! Is there anything I could do?

anas-diagnostics-20251008-2212.zip

Pinging @JorgeB

Edited October 8, 2025Oct 8 by apool

Still looks like a power/connection problem. Did you replace both cables for parity?

On 10/8/2025 at 10:37 PM, JorgeB said:

Still looks like a power/connection problem. Did you replace both cables for parity?

Yes, I changed everything. The only thing I haven't changed is the PSU. I have some DC to SATA converters, I'll power the disks with that and I'll report back...

Is there any way to check the error without having to do a full parity-check? It takes 18 to 20 hours to complete

If there are any new errors you can abort the check.

1 hour ago, JorgeB said:

If there are any new errors you can abort the check.

I know, but the errors only pop up at the end of the check.

They will show up on the GUI, Main page.

Well, I haven't had any luck with these. I had a SATA to DC adapter lying around, connected it to a faulty drive and started a parity check, also gave write errors at the end of the check.

What's surprising to me is that I can add these drives as data devices and it'll eat it up with no complaints:

I've purchased another 12TB one, different brand, and I'll use that one as parity, but it's really strange what happened with these drives