So, I ran into a peculiar problem while trying to get my homebuilt 4TB NAS up and running last night. I bought two 2TB SATA drives, and sourced everything else from my old computer boneyard (i.e. my closet). The issue I was having was the Ubuntu 10.10 Server installer kept failing when trying to install GRUB. I eventually tracked this down to an issue installing GRUB to GPT partitions (GRUB requires a BIOS boot partition). Since I’m running a small 5GB partition in RAID1 for Ubuntu, and the rest of the disks (~4TB) in RAID0, I’m exceeding the partition size limitations of MBR, and thus need to use GPT. Fine. The issue is that the Ubuntu installer seems to be unaware of how to handle this situation. Long story short, here’s what you need to do when yours fails: