Re: [gentoo-user] Re: Optional /usr merge in Gentoo

[pk]

On 2013-08-19 12:04, Alan McKinnon wrote:

> It's not that separate /usr is broken - it's not.

I know.

> The issue is a separate /usr without an initramfs. And the issue ONLY
> occurs at early-boot time.

It is broken for *some* systems.

> The problem is that with modern hardware much code that was
> traditionally stored in /usr may be needed early in the boot sequence,
> before /usr is mounted. The obvious case is firmware and drivers, and
> the usual example cited is bluetooth keyboards. If you need keyboard
> input at this time, you need to have the bluetooth daemon running, which
> is on /usr, which is not mounted.

Yes, bluetooth... the very thing that should not have come to pass. It
is broken by design. "Wireless" is fine but the way bluetooth works...
Back to the drawing board, please!

> The solution is to use an initramfs, and on a technical level it's not
> any different to needing a way to get the ext4 module off disk so you
> can mount /.

Yes, that is one way of solving it... But I question the sanity by
having ext4 as a module if you know you are going to use it on your
system; it's not as if you are going to use ext4 one day and reiserfs
the next day and XFS the day after that, or? The only ones that benefits
from that kind of setup is binary distros that can compile everything as
module and probe as they load.
I do however have some things compiled as modules (that I only load when
needed) but those things are not needed at boot. So for my case it's not
needed.

> Some may argue that bluetooth keyboards are a rarity and that's tough.
> Well, there's Macbook hardware, and phones which have soft keyboards.
> But many scenarios could exist, all due to the fact that hot-pluggable
> hardware can in theory run any arbitrary code to get itself up and
> running, and if that code is on a volume that is not mounted... The
> solution is obvious - all that code should be on / somewhere, or should
> be mountable using an initramfs.

Yes, *should* be. Quite optional. As it has "always" been. Just because
people are using bluetooth devices and/or want the computer to sing and
dance while booting should not impose restrictions to those who don't
want that, which is why I'm protesting.

> Do you see that although you and I can deal with this with relative
> ease, Aunt Tillie probably couldn't and the junior sysadmins I have to
> deal with certainly can't?

Yes. But have Gentoo ever been a distro for Aunt Tillie or junior
sysadmins? I don't want to discourage them to try it out of course but I
don't want to put restrictions on myself (or others) either...
Flexibility is the keyword here.

> Personally, I think that splitting / and /usr is a daft idea:

That's fine. I, respectfully, disagree. If I could break the system down
into bits and put each bit on a separate "harddrive" with a massive I/O
connection I would (yes, I exaggerate but I'm sure you get the idea).

> a. I have multi-TB hard disks, completely unlike the 5M monsters that
> Thomson had to deal with in the 70s

Haven't you heard? Size does not matter... ;-)

> b. I haven't had /usr break on me during boot requiring busybox in
> maintenance mode for at least 5 years. Every startup failure in that
> time required a rescue cd anyway, and I always have one of those handy

I haven't had /usr break either for at least that time even though I've
always had it separate. To me, I like to keep things organised in
different compartments using, perhaps somewhat arbitrary, rules.
Therefore keeping system administration tools in /sbin, user accessible
tools in /usr/bin etc. makes perfect sense (I know you think it's
arbitrary and I agree but it works, for me at least). There is no *real*
need to keep /usr separate for normal users it's just that I think it's
flexible and I want it that way. There is no right or wrong here, merely
philosophical differences. How you solve the different problems are
technical however. I do have a rescue USB stick handy as well though but
since I rarely use it I tend to forget to update it...

> c. it IS useful for terminal servers, but those tend to have experienced
> sysadmins, and they really should be OK with an initramfs (or their
> vendor should ship one)

Using an initramfs means you duplicate parts of your OS and copy them
into the kernel or using a tool (like dracut or genkernel). If you need
it from a technical point of view (bluetooth keyboard), that's fine but
if I don't have any hardware that requires it then why use an initramfs?
I guess it's a matter of taste (or "philosophy" if you will)... An
initramfs seems like bandaid to me (and it is).

> I'm often at the front of the Lennart-bashing parade, and what he says
> often makes sense but only in his narrow view of the world, but in
> *this* case, I can't help but admit he does have a point.

I don't really see it... I don't really care what Lennart does as long
as it doesn't affect me (and he may be the greatest person that ever
lived) but here we are... I choose to run Gentoo because it suits me
best of all the operating systems out there. If I didn't care about how
things works I would run Windows (or maybe MacOS).

Best regards

Peter K