Boot record

Does Xubuntu setup it's boot record with grub, or something else? I tried to get into the grub menu with sudo grub after booting the install disk, but that retued a command does not exit message, or the like.

Does Xubuntu setup it's boot record on the drive outside a partition, or within a chosen partition?

Also, is there a command to switch from 512 read/writes to 4096 read/writes once sector boundaries are straightened out?[