4

Aside from /boot, all my partitions (including root, /) are BTRFS subvolumes. I'm switching to BTRFS RAID1, and for the sake of integrity, want to include /boot within the BTRFS partition. Preferably as a separate subvolume (quota support) but possible as part of the root subvolume. I'm using the latest fedora, 22, which means:

  • grub2 2.02-0.16.fc22
  • btrfs-progs 4.0-1.fc22
  • kernel 4.0.4-303.fc22

Is this possible (yes/no)? Please provide information on any BTRFS+GRUB specific setup. I mean, creating a new subvolume and copying data is relatively straightforward, but getting the whole contraption to actually boot is another problem entirely.

Improve this question
5

Yes. Myself successfully moved /boot into the BTRFS system as a subvolume. No special consideration necessary - just don't forget to reinstall grub and rebuild the initramfs.

edit:

Will require running grub2-mkconfig -o /boot/grub2/grub.cfg after every upgrade involving a kernel (linux, memtest, etc) or during/after a fedora upgrade (fedup) as grubby does not support updating grub.cfg on btrfs subvolumes. There is a patch available [#864198 - see attachments] which hasn't been integrated because it's a hack. With kernel-install and BootLoaderSpec, grubby seems to be nearing end-of-life, so I don't find it objectionable.

TLDR:

Requires updating grub.cfg manually every post-kernel upgrade, which is painless unless you've directly edited it.

Improve this answer
1
  • Can you please provide detailed instructions on how you did this? It will be useful for many. – Ravi Aug 14 '15 at 18:14
1

It's a bad idea since you wont be able to use efistub and boot the kernel directly without using grub.

If you want integrity, you can use md raid1 for /boot

Improve this answer

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.