One thing that hasn't been mentioned yet is that btrfs is also
important for our plans to preserve system responsiveness under heavy
load,
https://pagure.io/fedora-workstation/issue/154.
On Fri, Jun 26, 2020 at 5:22 pm, Przemek Klosowski via devel
<devel(a)lists.fedoraproject.org> wrote:
For what it's worth, this is really needed, and overdue. I have
repeatedly failed Fedora OS release upgrades on different machines by
running out of root fs space. I think the default / is around 50GB,
and
it's too easy to fill: during OS update we need space for three copies
of each package: the old version, the downloaded new version, and the
space to install the new version.
We raised it to 70 GB, but it's still too small. I keep running out of
space too, most recently just a couple days ago. This is a problem
we're determined to solve, and raising the size of / further just
increases the chance of the user running out of space on /home
currently, so if btrfs doesn't pass, we will (very likely) switch to
single-partition ext4 (or maybe xfs). See
https://pagure.io/fedora-workstation/issue/152.