Hello. Maybe it will be useful for you. http://www.gnu.org/software/grub/manual/legacy/NetBSD.html I think you can try chain-loading. But I am not sure about how to do it on VPS.
Maybe relatives links: http://mail-index.netbsd.org/tech-kern/2014/05/16/msg017068.html http://mail-index.netbsd.org/tech-kern/2014/05/16/msg017071.html P.S. Grub2 and current work normal. https://help.ubuntu.com/community/Grub2%20Other%20Os#NetBSD izyk.
