I made mine 100MBs, which might be overkill. All you have in there are your grub files (size negliable), and your linux-mage thingys (kernels I think), which seem to be around 20MBs each. If you don't clean it out you're going to run out of space, but you generally only need one of them.
-- should warn at partitioning stage if /boot is on XFS https://launchpad.net/bugs/47848 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs