Btrfs as default filesystem for Fedora 23?

[Chris Murphy]

On Tue, Jun 23, 2015 at 2:15 PM, Neal Gompa <ngompa13 at gmail.com> wrote:

> Certainly, but with none of the features in Btrfs actually emitting scary
> "experimental" warnings anymore, and even all features working in btrfs RAID
> 5/6 now, I think we should really start pushing it to more people.

The multiple device stuff is no where near as feature complete in
failure contexts as mdadm or even lvm raid. There's no notification of
device failures that appear in GNOME, for example, which is the case
for mdadm managed devices.

There's been push back on the btrfs@ list about the wholesale dropping
of experimental warnings in particular with multiple device cases. So
just because there's no scary warning doesn't mean we know where all
the bodies are buried.

>Or at
> least develop some kind of test plan to prove the "worthiness" of using it
> as default. We must have something, ne?

Well the plan right now is deference to Josef Bacik. When he says it's
ready then I think the change can happen. But there are other factors
than this, and I think it's appropriate to have more clear criteria
than just what Josef says, that incorporates other concerns.

For example: Grubby doesn't grok Btrfs subvolumes, so /boot can't be a
Btrfs subvolume. So right now the installer proscribes it and uses
ext4 for /boot similar to encrypted root and LVM layouts. However, if
grubby couldn't boot from ext4 or XFS for some reason, it would be
considered a release blocking bug. Yet this bug [1] is routinely voted
as being release blocking, but then the grubby maintainer successfully
argues to make it not release blocking because after all Btrfs is not
the default file system so who cares that it doesn't work (basically).
So some features/bugs simply aren't going to get fixed until there's
the proper incentive, obviously.


-- 
Chris Murphy