About two years ago, I bought some Seagate Exos 2X14 ST14000NM0081 drives to build a new Blue Iris server, but couldn’t get them to work. Each drive only showed up as a single disk, not two 7 TB disks. I believe this was due to my H730 RAID card not supporting multi-actuator drives. I moved on with regular 14 TB drives, and hadn’t revisited this until recently.
A few weeks ago, I had an existing system that needed more storage, so I decided to make some use of those drives. I bought an LSI 9300-8i HBA card and some SFF-8643 to SFF-8482 cables:
Why LSI 9300-8i? Because I had used it in other projects, it’s affordable on eBay, and is listed in Seagate’s MACH.2 FAQ:
Q: What SAS HBAs have been tested with Exos 2X drives?
A: […] 9300 Series Host Bus Adapters
- Tested and confirmed compatible with multiple LUNs
The cables were specifically chosen to convert SATA power connectors to SAS.
Once the card and the cables arrived, I assembled them along with the hard drives into the existing system. The card was successfully detected, but the drives didn’t show up.
Actually, the drives just didn’t spin up.
I panicked for a few seconds, then searched online and learned about PWDIS or Power Disable. (The second link leads to a PDF download. Even though it’s from Western Digital, this feature could apply to new hard drives from any vendor.)
[…] if you put a new SATA HDD with this feature into a legacy chassis or enclosure, the drive may not spin up! The HDD is not defective. Some legacy power supplies provide 3.3V power on P3 (Pin 3), and this forces the HDD to get stuck in a hard reset condition preventing the HDD from spinning up.
So how could I verify if this was the issue? Online searches gave me two options:
- Permanently break Pin 3.
- Temporarily cover Pin 3 with a piece of tape.
Option 2 was the obvious choice since I needed to verify first and lacked the proper tools to break the pins.
But I didn’t have the right tape either.
I needed something called Kapton, which is supposed to provide good electrical insulation. But I had already waited several days for the HBA card and cables, I wanted to verify before waiting for another two days for the Kapton tape. I decided to use clear packaging tape as a proof of concept.
I covered all three pins instead of just Pin 3, because it was much easier to do it this way. It doesn’t matter because the first three pins are all for 3.3V and not used by 2.5’’ or 3.5’’ hard drives.
Now the drives were successfully recognized! I was able to create a ZFS pool and ran some tests, and everything looked fine.
I still bought a polyimide film tape and replaced my proof of concept a few days later. During those few days, the drives worked just fine. The small pieces of clear packaging tape also looked fine when I took them out.
Thanks to the cable and its connector, I could verify this without modifying my drives. If I went the other way to permanently break some pins, the drives wouldn’t have to be damaged either.
This is my final setup:
It’s an open computer case / test bench in an Ikea JONAXEL shelf. I’ll write about this system in the future. If you are interested, subscribe to the RSS feed, or just check back in a few weeks.