Does ROS 5.7 have any problem supporting a 500Gb HDD? The wiki says it supports "usually up to 120Gb" but I know it can support more than that as I am already running several x86 servers with ROS on 250Gb HDDs.

I think, ROS doesn't have limitation on HDD size. it either sees the HDD or not

http://forum.mikrotik.com/viewtopic.php ... lit=x86+gb

That's a guy who got a 1TB drive up and running using 5.0rc4, so 500GB on 5.7+ indeed shouldn't be a problem.