grub2 with gpt and bios_grub

peter:~ # parted /dev/sda print
Model: ATA Hitachi HDS5C303 (scsi)
Disk /dev/sda: 3001GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number  Start   End     Size    File system     Name       Flags
 1      1049kB  1573kB  524kB                   bios_grub  bios_grub
 2      2097kB  526MB   524MB   ext4            suseboot   boot, legacy_boot
 5      526MB   4564MB  4038MB  linux-swap(v1)  suseswap
 3      4564MB  2000GB  1996GB  ext4            suseroot

peter:~ # cat /etc/default/grub_installdevice
(hd0)
activate
generic_mbr