[gentoo-dev] Opinion against /usr merge

[Richard Yao]

Dear Everyone,

An often cited benefit of the /usr merge is the ability to put
everything but /etc on NFS and for that reason, we need to force an
initramfs on people happily using /usr without it.

Interestingly, the /usr merge changes made to genkernel permit us to
mount /etc from a genkernel-built initramfs by putting /etc on a
separate mount point in fstab and then doing `echo /etc >>
/etc/initramfs.mounts`.

Some people claim that the current approach is somehow broken by citing
Bluetooth keyboards. However, what makes that work is adopting an
initramfs and that does *not* require moving files into /usr. If people
do not want an initramfs, they can simply not have a separate /usr. The
/usr merge gives nothing to people using bluetooth while the /usr merge
will break systems of non-bluetooth users.

I have been told that moving everything into /usr would be easy for us
because Arch Linux did it and they are a rolling distribution too. Arch
Linux does all-or-nothing upgrades. They do not offer the ability for
their users to choose to use older versions of software and we will not
be able to move everything into /usr without breaking existing systems
that boot without issues now.

I have also been told that the /usr merge is necessary because upstream
will force it on us. Interestingly, most of @system on Gentoo Linux is
GNU software, which would need to stop supporting things in / in order
for that to happen. As far ass I know, systemd does not work on GNU HURD
and it would be incapable of functioning if the GNU project made this
change. Hell will freeze long before that happens.

The only thing that might require a merge is systemd and it is not in
@system. If we offered users the ability to choose rc systems, we would
still be supporting baselayout-1's rc system. If we start now, we should
bring that back.

With that said, there is a great deal of FUD being spread by the systemd
developers and I see no reason for us to accept it. We would be breaking
users' systems for no gain other than to make the systemd developers
happy. Their refusal to permit udev to be built separately from systemd
demonstrated complete disdain for Gentoo Linux. Why should we let them
dictate how we design our distribution at our users' expense?

Lastly, don't tell me to read systemd's case for why we should break
people's systems. I have read it and I find it flawed. There is
absolutely no need for us to make this change.

Yours truly,
Richard Yao