I am attempting to add two additional 12TB drives to my server. I cant get these two new drives to appear in the UnRaid GUI after installation. Before installing them in the case, I used a USB adapter and successfully connected both (separately). While visible in unassigned devices, I deleted old partitions (from synology usage) and formatted them in prep to add them to the data array.

I am running UnRaid 7.2.3 and currently have 2x 12TB parity drives and 4x 10TB data/array drives with a 2TB M.2 SSD and a 1TB WD Blue SSD for two separate cache pools (yes, i need better cache design). I have an ASRocks B460 Phantom Gaming 4 Mobo, i7-10700 with 64GB RAM. The two SSD's and four HDs use the six SATA connectors on the Mobo. The two current remaining HDs are connected to a LSI 9240-8i (in IT mode). The LSI card has just one of the breakout cables in use that came with the card - using P1 and P2. The server has been running great since build/install in late 2020.

I thought the install of two additional HDs would be straight forward other than needing a power cable adapter to have two additional SATA power jacks. I ordered a 1-4x SATA power adapter cable on amazon and went for the install. I mounted the drives in the HD trays for my Fractal Design 7 case, plugged in P3 and P4 cables from the LSI breakout cable and applied the power cables. Upon bootup, the drives do not appear. I thought it might be the 3.3v pin 3 issue so I pulled them back out and covered up pin three on both drives and reinstalled, booted up - still nothing. The other two HD's connected to the LSI card are still working normally and all four HD's connected to the LSI card are powered by the new SATA 1-4x power adapter.

I've considered connecting the second breakout cable that came with the LSI card but not confident that will do anything because I assume if there was a cable issue with the first one that's installed it would be one but not both and would also affect one of the drives that have been rock solid for five years.

I'm not sure what else to check or t/s. I've attached my system diagnostics in case that would help anyone that may have any insight.

Thanks in advance for any ideas

myunraid-diagnostics-20260111-1503.zip

27 minutes ago, jacksaudio said:

formatted them in prep to add them to the data array.

If you mean add to new slots in an array with valid parity, they will have to be cleared and then formatted after they are in the array.

29 minutes ago, jacksaudio said:

SATA 1-4x power adapter.

MOLEX-SATA power splitters are better than SATA-SATA power splitters.

Ideally, no more than 4 drives per PSU cable.

16 minutes ago, trurl said:

If you mean add to new slots in an array with valid parity, they will have to be cleared and then formatted after they are in the array.

MOLEX-SATA power splitters are better than SATA-SATA power splitters.

Ideally, no more than 4 drives per PSU cable.

@trurl - thanks for the quick response. I'm about to take the server down and try a few things.

I do have a molex-sata adapter and will try that next.

I wasnt aware teh preclear/format had to happen once added to the array. I precleared and formatted them via the usb adapter and in unassigned devices - guess I'll be doing that again once I get them to show up available to be added to the array.

Preclear can happen before adding to the array. That is why it is "pre".

If you add a disk to an array with valid parity, Unraid must clear if it hasn't been precleared. A clear disk is all zeros so has no effect on parity.

A formatted disk is not clear. It has an empty filesystem written on it, ready to store new folders and files.

Thanks for clearing up my confusion around clear/format. I did clear them via the USB interface but I guess I shouldnt have formatted them. Oh well.

That said...anyone else have any suggestions to get these two addl hard drives to appear in UnRaid? I've swapped to a new molex power cable for the two hard drives and I've even tried the second break-out cable from the LSI controller

Can you see the drives in BIOS?

1 hour ago, trurl said:

Can you see the drives in BIOS?

As far as I recall, The "new" drives are not visible in the BIOS - only those that are directly plugged into the motherboard. However the two hard drives also on the LSI card that ARE working and have been in UnRaid for over four years are not visible in BIOS either. I can check again later tonight or tomorrow morning...too many family members on my server this afternoon.