So it will be the latter, as it will run nextcloud, a couple websites i have, a pihole and possible game servers when the need comes again. For the websites i plan on using the mass storage as a backup to the sites' data, so the actual running files will stay on the ssd running the os, currently considering proxmox actually.
for nextcloud i am not sure, since i use it to sync, and 'backup' (i know its not meant as a backup program), so it would need lots of random r/w, but it cant fit on the os ssd as that would get too large, currently only have a 250gb ssd on hand for the os.
Id love to get ssds instead of mass storage hdds, but theyre simply 3 times as expensive for the same storage which is out of budget for me.