Install 2nd EOS into a custum BTRFS subvolume

[theodore1]

Hello
Beside my main EOS system I would like to have a second system for testing different desktop environments.
Until now I did this with a different partition, but I thought I could do this a different btrfs subvolume. But I failed so far.

I booted into live usb and tried this:

sudo cryptsetup luksOpen /dev/nvme0n1p5 luks-root
sudo mount -o subvol=/ /dev/mapper/luks-root /mnt
sudo btrfs subvolume create /mnt/@hyprland
sudo umount /mnt
sudo mount -o subvol=@hyprland,compress=zstd,noatime /dev/mapper/luks-root /mnt
sudo mkdir /mnt/efi
sudo mount /dev/nvme0n1p1 /mnt/efi

And after that I started Calamares, chose manual partitioning and mounted the fat32 partition at /efi and the whole btrfs partition at /
I thought the above mount would make @hyprland subvolume as the new root.
But the installation failed (error: main script file /usr/lib/calamares/modules/mount/main.py for python job mount raised an exception).

How can I install a new system into a new subvolume (@hyprland)?
Because it’s a test system, I don’t need other separate subvolumes, like @home, @cache or @log.

Thanks a lot!

[dalto]

You need to setup the subvolume config you want in /etc/calamares/modules/mount.conf

You also need to make sure that the subvolumes you are installing into don’t exist.

I am not sure if it is possible to install into an existing encrypted volume though. That would require some testing.

[theodore1]

Thanks dalto!
I succeeded to install it on subvolume on an un-encrypted partition but failed on the encrypted one.
I edited mount.conf file:

mount point: /
subvolume: /@hyprland

Then in calamares I mounted /efi and / as usual.
I guess I don’t need the encryption after all, just the subvolumes.