Internal boot drive for TrueNAS on HPE ProLiant Microserver Gen10 Plus (and internal 5V/12V power)

[GardG]

Hi all

I'll be setting up TrueNAS on a Microserver Gen10 Plus, and I'm contemplating what to use as the boot drive. I want something internal to prevent accidental disconncetion, but I'll be using all the drive bays for storage spinners, and the PCIe slot for a 10GbE SFP NIC.

That leaves me with only the internal USB2 port. Speed-wise that should be OK, it doesn't really matter (but WHY is it not USB3??). I'm considering using an USB-mSATA adapter, which should be small enough to fit. I guess a single small mSATA drive should be able to be bus powered by the USB2 port.

For redundancy I could mirror to a second external USB adapted mSATA drive. A more elegant option would be putting something like this with two mSATA drives inside the unit. However I highly doubt a regular USB2 port could reliable power two mSATA drives and the RAID controller.

This leaves me with two questions:

1) How much current can the internal USB2 port deliver?

2) What other power rails are available inside the unit?

I don't have the Microserver yet, but as far as I can tell there's a (presumably) 12V+5V connector for the backplane which appears to be a Molex MiniFit. I guess in theroy I could use a Y cable on that one and grab a few watts off the 5V rail for my boot drives. That would be easy and completely reversable, but I guess it's a potential warranty voider?