Install btrfs over two nvme

During install how do I setup a BTRFS over two nvme? I can select two dev in lvm but btrfs has no option to select more than one device.

It’s dangerous. If one of the two drives fails, all data is gone.

I am not familiar with the options of btrfs as I am not using it, but you can certainly create LVM volumes (which you do anyway should you select Encryption) and have the volume group (VG) span over two drives. Btrfs doesn’t even see them as two drives then, but as a single volume.
This would work, but I advise against it.

RAID 1 is redundant storage which allows for any number of devices where all but one can fail. It is very safe in that way.

So, you don’t want to span your pool over two drives (“stripe”) but mirror the two drives (“RAID1”)?

Sorry for misunderstanding your initial post.

Ended up doing this:

but thatn anaconda failes miserably

install on a single btrfs drive and add the 2nd device later with btrfs command converting to a RAID1 setup.
Oh and you don’t really need LVM when handling btrfs devices.

4.2 MB for /boot?

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ok it needed a bit of prep before anaconda partition editor was able to make sense of my aim but here we are

# lsblk -f
NAME    FSTYPE FSVER LABEL   UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
sda                                                                              
├─sda1  vfat   FAT32 EFI     9D76-93D5                             579.5M     3% /boot/efi
├─sda2  ext4   1.0           8c189042-dd69-4ced-ada6-50edaf4b2d5c    1.3G    24% /boot
└─sda3  ext4   1.0   @root   5507e127-d8d0-4d9c-9740-9a3895c400cc   81.8G    23% /
sdb                                                                              
├─sdb1  exfat  1.0   Ventoy  4E21-0000                                           
└─sdb2  vfat   FAT16 VTOYEFI 3105-B091                                           
sdc     vfat   FAT32 USB4    2408-59E0                                           
zram0   swap   1     zram0   943163d7-0b5e-4870-b23a-c5b2702ef08d                [SWAP]
nvme0n1 btrfs                9824f397-8933-4c17-94fe-512528631323                
nvme1n1 btrfs                9824f397-8933-4c17-94fe-512528631323  456.9G     4% /var/log
                                                                                 /opt
                                                                                 /var/cache
                                                                                 /var/lib/libvirt
                                                                                 /var/tmp
                                                                                 /home

and it seems to do raid

# btrfs fil df /home
Data, RAID1: total=21.00GiB, used=18.96GiB
System, RAID1: total=32.00MiB, used=16.00KiB
Metadata, RAID1: total=1.00GiB, used=44.47MiB
GlobalReserve, single: total=21.77MiB, used=0.00B

and there is quite some room

# df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda3       114G   26G   82G  24% /
devtmpfs        7.8G     0  7.8G   0% /dev
tmpfs           7.8G   41M  7.8G   1% /dev/shm
efivarfs        128K   83K   41K  67% /sys/firmware/efi/efivars
tmpfs           3.2G  2.1M  3.2G   1% /run
tmpfs           1.0M     0  1.0M   0% /run/credentials/systemd-journald.service
/dev/sda2       2.0G  469M  1.4G  26% /boot
tmpfs           7.8G  2.9M  7.8G   1% /tmp
/dev/nvme1n1    477G   20G  457G   4% /home
/dev/nvme1n1    477G   20G  457G   4% /var/tmp
/dev/nvme1n1    477G   20G  457G   4% /var/lib/libvirt
/dev/nvme1n1    477G   20G  457G   4% /var/cache
/dev/nvme1n1    477G   20G  457G   4% /opt
/dev/nvme1n1    477G   20G  457G   4% /var/log
/dev/sda1       599M   20M  580M   4% /boot/efi
tmpfs           1.0M     0  1.0M   0% /run/credentials/systemd-resolved.service
tmpfs           1.6G  208K  1.6G   1% /run/user/1000
tmpfs           1.6G  160K  1.6G   1% /run/user/0

What is totally confusing is that anaconda at some point claims to have a 1TB device which would imply RAID0. Not what I want.

have you tried with iso netinstall and blivet-gui?

No, should I. What is blivet-gui’?

Btw really silly. I made quite a few captured instals but while cleaning up deleted the ones where anaconda failed.

this one worked 2025-11-30 14-38-22Fedora Budgie Anaconda error

and I filed a bugreports agains buzilla.redhat.com 2412715 – WebUI: TypeError: Cannot read properties of undefined (reading 'v')

This is your btrfs volume and 477G are available across ALL subvolumes.

try sudo btrfs fi usage /home, this should show both btrfs devices.

I don’t quite undestand the decision to use ext4 for / but otherwise this looks ok.

I’ve always had trouble with WebUI Anaconda. Blivet-gui is the interface present in Fedora 41 ws and earlier. I’ve always preferred Blivet-gui.

the reason is that I believe, perhaps wrongly, ext4 more robust.