Hey guys.
I’m trying to install Manjaro in my new Laptop and I couldn’t do that.
I have 2 NVMEs and I tried to install as LVM and as root and home partitions separated in each disk. Nothing works.
How I want use BTRFS partition, ever the same mistake is showed.
“It is not possible to create subvolume for…”
I also searched on Web if there is a problem seems like with mine but I don’t find a solution that resolves for me.
Can you help me?
Can you show what is the output of lsblk -f after installation Manjaro?
Hey @Donadon 
Why LVM, when you use BTRFS? Makes no sense. BTRFS can use more than one device. You could simply install Manjaro with BTRFS on one NVME and add the second device. Then you switch the profile to DUP, RAID0/1.
Please explain what your goal is.
What @megavolt said…
BTRFS filesystems across multiple drives with RAID 0 or 1 (striping or mirroring) has been stable for quite some time. When you’re doing things like RAID 5/6, that is when you would want to do BTRFS over LVM. (Though that won’t be the case in the foreseeable future.)
Not sure if the installer does this for you, but the setup for 2 drives is very simple. e.g.:
mkfs.btrfs -m raid1 /dev/part1 /dev/part2
RAID 1 obviously halves your usable space (while increasing read speed), but one drive can fail. While RAID 0, which might be what you want to do? Would make it so if either drive failed, you would lose everything. (Though you would increase write speed.)
If you wanted root and home on different drives for another reason, that’s just creating 2 different BTRFS filesystems on each drive. Either way, there is no need for LVM in any of these scenarios.
Install manjaro with the ISO on 1st SSD (ignoring the 2nd SSD)
Start and configure your system as you want
After all is done (in the running system) do:
create a new partition table for 2nd SSD
create an empty, not formatted partition on it
add this partition as 2nd device to your existing btrfs-volume
Change RAID-level as you want
Balance