Q: How do I give non-root users write access to my /usr2 filesystem (shared with NT)? I'm attempting to install Oracle.
A: I'm assuming you are trying to use a VFAT filesystem under Linux. This is not optimal, and FAT is less stable than ext2 or NTFS. Of course, NT can't read ext2 partitions, and NTFS is still experimental under Linux.
As far as ownership goes, Linux assigns a uid, and gid of 0 by default. The mount manpage lists the options for FAT file sytems. Options you should look at are uid=(some ID), gid=(some ID), umask=(value). Then, as you need those options, add them to /etc/fstab .
Example:
/dev/sda1 /stuff vfat user,uid=(something) 1 0