Missing Drive

no_strings

I'm afraid I know the answer, but asking in case someone knows better. This will be one of the rare situations where I'll be happy to be wrong.

My server mobo is a Mitac PD10EHI. It's been running off an M.2 SSD which is now out of space. The board has two SATA connectors so my plan was to add two 2.5" SSDs and mirror them and use an external, portable spinning brown round for backup. In case of fire evac, I grab the HDD and run.

After adding the two new SATAs, only one is showing up. One of the new ones is /dev/sda and the M.2 is now /dev/sdb. I Googled and Gemini said, "Of course, you can use the M.2 and two SATAs" but added some cautionary gobbledygook about checking my board specifications. The company sells finished systems and lets me build a configuration that matches mine, so I'm still thinking I'm OK.

The manual says this:
SATA 3.0 Gb/s port (multiplexed with an mSATA slot)
SATA 3.0 Gb/s port (multiplexed with an m.2 slot)

Means I can use one or the other, but not both?

Thanks.

PL1

no_strings Means I can use one or the other, but not both?

I think you are limited to two devices. I was reading the MB manual and it is not very clear. But, the spec sheet shows the two SATA drives are shared, one with the M.2 and one with mSATA. I think where it says shared it means one or the other. But I don't really know for sure. Here is the part I'm referring to.

https://download.mitacmct.com/Files/datasheets/motherboards/PD10EHI.pdf

But it also shows that it supports 2 M.2 drives and 2 SATA III drives.

no_strings

Thanks. That's how I'm reading it as well. Major buzzkill but I can still make it work. It's just going to be a lot harder.