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View Full Version : [all variants] 11.04 GPT bios boot partition mirroring ?



declanmullen
May 3rd, 2011, 03:27 AM
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
May 3rd, 2011, 03:45 AM
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 (http://en.wikipedia.org/wiki/GUID_Partition_Table) or use the GPT fdisk (gdisk) (http://www.rodsbooks.com/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.