Is it possible to boot with only 48M of RAM in a DragonFly system? Probably not. 128M would be better. I usually talk about the lower memory limit for Hammer, since it’s so relatively low for a snapshotting file system, but the converse applies here. 128M is probably the comfortable lower limit, though it’s pretty hard to find a system that would limit you that way without doing it on purpose. 128M sticks of RAM are practically disposable these days, really.