Arch Linux

Nvveen

Member

Registered: 2010-06-14

Posts: 11

LVM, Grub2, BTRFS and dm-crypt.

Hello,

So the other day I was wondering about my Arch server, and how I would like to reinstall the system with the newest in Linux booting and filesystem facilities. So before I wiped it clean, I created a Virtual Machine (yes, I'm cautious) that emulates the hard-drive setup of the server, namely two physical HDDs of differing sizes.
So it got me wondering about BTRFS and Grub2. Grub2 because it allows me to have a resizable /boot partition, and BTRFS because it's BTRFS. I also started formulating a plan, which went something like this:

Join the two HDDs under LVM into a big pool under /dev/lfsvol/ with two volumes, /dev/lfsvol/boot and /dev/lfsvol/encrypted. Then, encrypt the encrypted volume, and use BTRFS to pool the /dev/mapper/decrypted device so a set of subvolumes can be created as /home, /root, and swap. Mounting all of this under a directory isn't hard, and I did manage to install an Arch base system on it. The problem, here, is booting. What changes do I have to make in grub.cfg and mkinitcpio(-btrfs) to allow for all of this?

Failing that, maybe someone can give a different, better way of installing Arch, but with the following requirements:
- /boot needs to be resizeable
- No striping of data, so the two HDDs need to be pooled into one big chunk of memory.
- Encryption is needed on everything (except for boot, as I understand Grub2 doesn't like that).

Failing the previous as well, I can always revert back to making a separate /dev/sda1 boot partition, and pooling /dev/sda2 and /dev/sdb1 with RAID/LVM, encrypt the device and subpartition the decrypted volume with LVM, but where's the fun in that?

Thanks in advance,

Neal van Veen.