Which boot manager is used by OpenSolaris?
OpenSolaris uses GRUB boot manager. Warning: any existing boot manager will get overwritten by the OpenSolaris installer. Backup your existing boot loader configuration if you already use a boot loader. This is especially critical if you run Linux which uses it’s own boot loader. If you use GRUB in Linux it is vital to save a copy of GRUB’s menu.lst. This file is usually stored in /etc/boot/menu.lst on Linux or in /rpool/boot/grub/menu.lst on OpenSolaris. Copy this file on a USB stick, it will be easy for you to get it back in case you need it (you can also copy it onto the network, however you may have initial issues with accessing network from OpenSolaris so a USB stick works better). If you use Lilo, Windows boot loader or other custom boot loader follow backup instructions for these boot loaders.