Looking for recommendations on how to install SLES11SP2 on a 3TB drive. The drive is a raid5 array made up of 600 GB drives with a single 2.7 TB logical drive. We would like to make it one single root partition but I'm having problems getting it to boot. I've tried:

GPT: 2 GB swap, 2 GB /boot ext3, and ~2.7 TB /root both btrfs and ext3.
MBR: 2 GB swap, but can't use more than 2 TB of the disk.
GPT: 2 GB swap, LVM with 158MB /boot and 2.7 TB volume (10 GB /root).
GPT: 2 GB swap, 1.99 TB /root ext3, ~800 GB /data ext3.

The first attempt at least booted once then couldn't find the boot device after installing the Service Pack for Proliant packages. All the rest just go into attempting PXE boot after the initial install first reboot. We really didn't want to break the raid into two logical drives, but for no real reason. Need help in a hurry, the server owner is threatening to install Windows!!