booting nixos from lvm on top of mdadm
09 apr 2012
what is this?
since i might require such an setup more often i post it here, so i don’t forget it (see [1]).
this guide works great for fdisk+mdadm+LVM but it did not work for parted lately using ubuntu server. i don’t know why, maybe because of the raid controller?
in case someone removes the commands from the nixos wiki, here are the commands again:
mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1
pvcreate /dev/md0
vgcreate myvolgrp /dev/md0
lvcreate -L 1G -n boot myvolgrp
lvcreate -L 5G -n system myvolgrp
mkfs.ext4 -n boot /dev/myvolgrp/boot
mkfs.ext4 -n system /dev/myvolgrp/system
mount -L system /mnt
nixos-option --install
cat /etc/nixos/configuration.nix
...
{ mountPoint = "/";
label="system";
}
{ mountPoint = "/boot";
label="boot";
}
nixos-installadvantages of this setup
- no special partition required either something like /dev/sda1 or /dev/sdb1 where /boot would be placed on
- LVM can be used for anything
- still mdadm is below, which is a good thing
reminds me though that i should check if /etc/nixos/configuration.nix is capable of installing grub in several partitions already. usually it is only installed in /dev/sda given by this example:
boot.loader.grub = {
# Use grub 2 as boot loader.
enable = true;
version = 2;
# Define on which hard drive you want to install Grub.
device = "/dev/sda"; # here is only one partition given
};