11.04 GPT bios boot partition mirroring ?

[declanmullen]

I'm doing a fresh install of xubuntu 11.04 x86 32bit via the Alternative CD. My computer has two 2TB drives and I want to mirror the partitions for redundancy.

For the Linux partitions (ie root and swap) I'll be creating raid partitions on each drive and using software RAID 1 to create md partitions of type ext4 and swap.

For the GPT's bios boot partition, am I also meant to use software raid ? Ie create a raid partition on each drive and use software RAID 1 to create a md partition of type bios boot ?

Or am I meant to not use raid partitions and just create a bios boot partition directly on each drive ? In this case, will xubuntu's install process and grub tools ensure that both partitions contain the relevant grub files or do I have to explicetly do somthing to ensure that ?

Thanks,
Declan

[srs5694]

You can't create "a md partition of type bios boot" because the identification of a "RAID partition" and of a "BIOS Boot Partition" both rely on a GUID partition type code. Unfortunately, libparted-based tools make this fact as clear as mud, but you can check the GUID type codes on the Wikipedia entry for GPT or use the GPT fdisk (gdisk) partitioning tool instead (it shows the GPT data structures in a way that's much closer to reality).

I have next to no personal experience with Linux software RAID on GPT disks, but it's my understanding that if you create a BIOS Boot Partition on each disk and then install GRUB simultaneously to both disks, you'll get everything set up so that either disk can boot. I don't know if the installer does this automatically, though, so you might want to manually re-install GRUB after you've set everything up.