If you use the “custom” partitioning UI during installation of Fedora 34 and change the name of any btrfs subvolume, its line in
/etc/fstab will lack the intended compress=zstd:1 mount option. This is benign, affecting only fstab entries, unless the subvolume is mounted as root (
/ ); in this case, the entire installation will lack compression.
Bugzilla report: #1952764
If you need to change the
/ subvolume name, e.g.
@root there are a couple of workarounds for the bug:
- Step 1: Modify the Name field for ‘/’ mount point, per user preference.
- Step 2 (optional): Immediately after beginning the installation, switch to a shell and enter:
sudo mount -o remount,compress=zstd:1 /mnt/sysimage. If you get an error, you were too fast, the installer hasn’t yet mounted the Btrfs file system to
/mnt/sysimage- simply reissue the command until it returns without error. You can confirm it’s enabled by
mount | grep btrfs.
- Step 3: Modify
/etc/fstabpost-install, either before or after rebooting from the install environment.
- Step 1: Proceed with installation normally, do not modify the subvolume name for
- Step 2: Post-install change the name of the
/subvolume found in the top-level of the file - system, and update
/etc/fstabto indicate the
NOTE: It is safe to rename actively mounted subvolumes.