Hello,

I've had ongoing issues with disks being disabled on my server. If possible, I am looking for guidance on 2 issues; one immediate, and one to try and the other long-term resolution.

Immediate issue:

Overnight my dual-parity server was running some of it's maintenance routines (backup & mover) when I had 2 data disks become disabled: Disk9 @0418 & Disk5 @0431. This comes on the heals of 2 other drives becoming disabled several weeks ago. I mention this other recent failure because one of those failures was a parity drive (Parity2) I had purchased new back in August after an even earlier drive failure. Because the 2 Parity drives I had were new since Aug (and expensive) I made the assumption they would be fine. What I did was move all the data off the one failed data drive, then removed it from the array. I then left the 2 parity drives in place and rebuilt parity with the new smaller array. When parity was done rebuilding all drives were showing good except Parity 2 which was enabled but showing 1024 errors. As you'll see in my current logs, and the below screen shot, that number appears to be related in a way that seems far from coincidental:

So with the immediate issue I'm hoping to get your guidance on what you think the state of these drives might be and the safest way to proceeded in getting my data back to a proper protected state. I'm extra concerned because the current failure seems to be tied to the parity drive errors even though that Parity drive seems operational.

Long term-issue:

The ongoing issue I'd like to troubleshoot is that the problem of drives being disabled is one I haven't been able to solve since I built the server 7 years ago. This was my first server and so I have been learning, but this problem persists. I believe it's most likely power as that's what I hear is the most common reason for UNRAID to disable a drive; however, what I'm not sure about is if these seemingly minor power inconsistencies would lead to drives becoming inoperable? In the 7 years I've been running this server I've had 4 or 5 drives become unusable after becoming disabled the first time (meaning they wont pre-clear or rebuild into an array due to errors) despite the fact that I can mount them as unassigned devices and see the original data still there. Can an inconsistent power issue result in drives becoming destroyed or corrupted in some way that also makes them unusable or is this indicative of a some other possible issue? Aside from the recent purchase of used 12TB drives earlier this year (one of which wont rebuild anymore), all my drives have been purchased new. I just seem to have an unusually high failure rate.

Additionally, I ran the server for 5+ years with all 11-12 drives running off of a single power connector from the power supply because I didn't know what I was doing (and obviously still don't). In that time I didn't have disk spin down set up for the array, so all disks would run at all times. Yet, in those 5+ years I had maybe 4 instances of drives being disabled? Since then I did set up a disk spin down and have split off 3 total power runs from the power supply but I seem to have disks disabling more frequently now and it always seems to be 2 drives at the same time or in quick succession. This has obviously become very frustrating because I'm spending a lot on drives that wind up in the trash and it's always a panic state with my data. Any help on troubleshooting would be very much appreciated.

I haven't dine anything and have attached the diagnostics.

calculon-diagnostics-20251201-1014.zip

It does look like a power/connection issue, any power splitter in use? Could also be a bad/weak PSU or a miniSAS cable. Check/replace the cables, remove any splitter if in use, and/or use a different PSU if you have one, then post new diags after array start.

Thank you for the quick response. I know I through a lot at you.

For power I'm using a 750W EVGA power supply. I wouldn't know how diagnose any issues it's having other than sound and it sounds fine. I believe it's more than a enough theoretical power for the use case. I am splitting the power though using these:

https://www.amazon.com/dp/B012BPLW08?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_32

Data is being managed through a 3GB/s HBA SAS expander using these cables:

https://www.amazon.com/dp/B013G4FEGG?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_31&th=1

I was troubleshooting this issue with a friend as well and he identified that I have several 6GB/s drives which can apparently encounter handshake issues when the drives spin up/down while interacting with a 3GB/s HBA. Is this a known issue that could be responsible for frequent disabling of drives by UNRAID? I am considering upgrading to a 12Gb version.

Edited December 1, 2025Dec 1 by beatmurph

12 hours ago, beatmurph said:

Is this a known issue that could be responsible for frequent disabling of drives by UNRAID?

It's not a typical issue, though drives getting disabled during spin up can happen with some disk/HBA combos, but I don't see that in your diags. i.e., the drives did not get disabled after a spin up command.

Thank you for the clarification Jorge. As always I appreciate it. I am still going to update the HBA to a modern 12Gb version as they are cheap. In addition, I will contact EVGA to see about getting 2 addition SATA cables. I do have 5 SATA/PERIF outputs on my power supply but only 3 SATA cables. This is why I'm running 3-5 drives off each cable. I will also purchase all new splitters. Hopefully getting the down to the 3 drives/PSU cable with new cabling will help.

OK, this is a new one to me. Yesterday I had stopped my array for a bit, then I restarted it. I believe it was at this time that the I received this alert from the server:

Event: Unraid array errors
Subject: Notice [CALCULON] - array turned good
Description: Array has 0 disks with read errors

Can you help me understand? How did the read errors just dissapear? I didn't realize that could happen. Do you have thoughts on what that could potentially mean in this case? The 2 data drives are still dissabled, but it is accurate that no read errors are displayed in the UI.

calculon-diagnostics-20251202-0927.zip

Edited December 2, 2025Dec 2 by beatmurph
I meant to attach diagnostic, they are attached now. Also, that alert came in at 5:28PM yesterday.

30 minutes ago, beatmurph said:

How did the read errors just dissapear?

Array disk errors are reset at every array start, not sidabsled disks, just errors for disks that are still enabled.

Oh, I guess I never noticed that. I only recently set up my alerts so that's what caught my attention. Thanks again

20 hours ago, beatmurph said:

I am splitting the power though using these:

https://www.amazon.com/dp/B012BPLW08?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_32

They might well cause a problem. We tend to never recommend splitting a SATA power connection more than 2-way due to the limited current the SATA connection can carry. If you use Molex->SATA splitters you can normally get away with a 4-way split without issues as the Molex connector is more robust.

That's interesting. I actually had previously tried to use the molex->SATA power cables included with my power supply so that I could reduce the amount of splits. Unfortunately every time I powered on the sever one of the drives wouldn't show up (I don't recall exactly how it was represented in the UI, but I think as just not present). After 3 attempts to reseat and double check everything I gave up and went back to the 1 into 5 SATA set up I'm currently running. Obviously I'm still running into disable issues, but at least all the drives are present. Perhaps I should instead see if EVGA will send more molex cables instead.

3 minutes ago, beatmurph said:

actually had previously tried to use the molex->SATA power cables included with my power supply

Do you mean quite this? I would normally expect a single PSU cable to have either Molex or SATA connectors on it (not both) and the PSU to not have included Molex->SATA adapters.

A cautionary word - II your PSU is a modular one make sure you use compatible cables. There is no standard for modular supply cables (even for different models from the same manufacturer), and getting the wrong one for your PSU can result in fried drive electronics.

I did meant it, but it sounds like there may be necessary detail that is still only in my head. I'll try to provide as much as I can here:

PSU: EVGA Supernova 750G+ (modular)

This has 5 total (3xSATA & 2xPERIF) connectors which I understood to be identical

The PSU came with 3x SATA cables which end in 3 connectors, as well as 2x molex cables which also end into 3 connectors

What I had done previously was purchase Cable Matters 1-to-1 molex to SATA adapters and attach them to the 2x molex power cables (connected to the PSU PERIF connector) so I was running 5 total cables from the PSU (3 drives per cable). This is when the 1 drive would not show as present after reboot.

I'm doing some digging now and it seems the PERIF connector on the PSU end is different in that in may not have the 3.3v pin (makes sense). Since I have a mix of SAS/SATA drives, it's possible the drive wasn't showing without that 3.3v pin?

My current request to EVGA is though my product registration for this specific PSU, so the request is hopefully a clear attempt to get cables specific to this power supply. I had read EVGA is a good company and willing to do that. I'm not sure if that's true, but I guess I'll find out.

120-GP-0750-X1.pdf

Edited December 2, 2025Dec 2 by beatmurph
I'm not sure if you care, but I've included the manual from EVGA

I missed the power splitter before; I thought the link was to the PSU. You should really avoid those; SATA cables should never be split into more than two plugs, and even those should be avoided when possible.

So I was able to swap my HBA SAS expander to a newer 12GB/s version (for what that's worth) and was able to get my drive power split down to 3 HDD per rail. It's been a little over a week and no drive issues yet - fingers crossed. Unfortunately I did have some issues with the parity rebuild, and am now having strange behavior that seems to be worsening.

This issue can be closed though.So I was able to swap my HBA SAS expander to a newer 12GB/s version (for what that's worth) and was able to get my drive power split down to 3 HDD per rail. It's been a little over a week and no drive issues yet - fingers crossed. Unfortunately I did have some issues with the parity rebuild, and am now having strange behavior that seems to be worsening.

This issue can be closed though.