Can't install to BTRFS when using custom partitioning

I am only able to use BTRFS if I use Automatic partitioning.

  1. When using custom the drop down list excludes btrfs. It only lists extX, vfs, fat, xfs.
  2. If I format to btrfs outside of the installer, the installer WON’T let me “reformat” it’s greyed out plus it won’t let me set the mount point to it.

So I can’t find a way to install to a btrfs partition other than automatic.

Hi,

For case 1:

If you want to use btrfs, leave the selection to btrfs and don’t change it. Then click “Click here to create them automatically”. After that you could customize the size of each partition by click “Modify” button. Don’t forget to click button “Update Settings” each time you finishing the modification.

For case 2:

If you create partition outside the installer, It will be lot easier if you use “Advance” mode instead of “Custom” (very right of choices). From there you could assign the mounting manually.

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Hi welcome to :fedora: community
Thanks for writing us.
Can you attach some screenshots so that we can figure out what is going on.what kind of error anaconda showing you

If you have a btrfs partition already it should allow me to merely set the mount point, click update and done. But if my partition type is anything else it works - but BTRFS won’t allow me. In addition you can see the “reformat” button is greyed out.

If I have any other filesystem I can reformat as other types but not btrfs. As you can see it’s not in the list.

Thanks I am aware advanced can do this as a workaround however I think that “custom” should be able to work for BTRFS the same way it can for ext2/3/4,xfs etc. I should just be able to set a mount point and go

I just try it in VM, and I also have the same problem. The only way to do it from Custom menu is by creating directly on this menu by clicking the [+] button and choose btrfs.

Maybe you could report it to bugzilla specified to anaconda(?) installer here if you feel this should be works.

2 Likes

To explain what is happening here, there are two ways you can use btrfs:

  1. As a simple filesystem. One device (partition) formatted to btrfs using mkfs.btrfs without using any special features of btrfs.
  2. As a volume management “tool” similar to LVM. Btrfs allows you to combine multiple device to one volume, setup RAID levels and configure multiple subvolumes on top of the volume.

The custom partitioning in Anaconda doesn’t support the first use case. That’s why you can’t create a partition formatted to btrfs (or reformat existing ext4 partition to btrfs). Anaconda supports only the second use case, this is also how the default btrfs layout works – you have one partition with two btrfs subvolumes for / and /home. To add a new btrfs volume you need to switch the partitioning scheme to Btrfs and then use the + button to add a new one as pointed out by @oprizal.