I’m pretty sure that one would not work properly with freenas so I have been looking at other cards that should do the job as the backplane only has 2 mini-sas connectors. (part number: 684886-001)
I’m pretty sure the LSI HBA would work. I think it’s the same one that I’ve been using for some time now. I believe I got it off of eBay as well but I can’t find the listing in my purchase history at the moment. The HP card my still work but you’ll need to check to see what type of controller is used on it. Someone on the FreeNAS forums would probably be able to tell you.
Freenas will work with most LSI 2008 rebrands.
The problem might be whether the machine itself will play nice with the card.
I would check places like servethehome and maybe r/homelab, but they might not be welcoming of new landers, so search first?
Yeah I don’t see why that hba wouldn’t work, although I’ve never used HP servers. You are correct that it will only support 8 drives without a multiplier.