System unresponsive, USB Booting OS failed - again.

[ubuntumuntu]

(Server's offline atm, so going by memory a bit here, so please bear with me)

I've a 'new' HPE microserver (gen.10 IIRC) that I've loaded with 4 WD's (4GB?), in a ZRAID config, one of which is a hot spare.
I've opted to replace the optic drive with a SSD for.... SSD stuff.
Been running a few jails & the like.

OS boots off a (8GB Kingston) USB drive, which resides on the internal USB port.

So far so good - system has been mostly copacetic for a few months.

Came back from week-long trip, with box being unresponsive: oddly, I can access a few of the jails running on it (eg. Docker, Plex), but not the host itself. I could ping the box, but not SSH into it.
Tried plugging in a keyboard & blindly ctrl+alt+del rebooting, but no dice, so forced to do a hard reboot.

Does not come up nice - think it was complaining about UEFI or something. If I set BIOS to legacy, still no dice; I think it registered all drives, including the OS on USB, as FreeNAS data disks & halts.

I recall I had a similar experience a few months back & had to rewrite a new OS & import disks (OK), but lost some configs.

What's going on here?
Why does this happen, seemingly out of the blue.

I'm elbow-deep in the guts of some machines so just dropping some info as I recall it between rebuilds, so please be patient if I need to supplement additional info.

P.S assuming FUBAR boot USB, is there a way to run a backup USB? not a mirror, as I don't want to copy bugs, faulty config or other corruption, but something I can use to get my system u p& running in short order?

 

[ThreeDee]

An SSD is recomended anymore .. if you are out of sata ports, like I am, you could try a USB to SATA cable to run off your internal USB port.. I picked up a couple 128GB SSD's for 20 bucks used off of a forum over 6 months ago .. made one my new boot drive and it's been rock solid since initial install

 

[ubuntumuntu]

It looks like the USB media the OS runs off - sitting internal of box on mobo - got cooked somehow.
The SSD is used for caching purposes & to host my containers' OS's (data still on striped volumes).

On my pfSense box, I have a plugin (? IIRC) that automagically backs up my host config, so that if/when I fry the box, it's not a huge loss. Unsure if FN has a similar function.
I've managed to bring my box up again OK, but my last backup looks pretty old - around 6 months, though I don't think I've messed around too much with the host since then.