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Re: e2fsprogs as Essential: yes?: Maybe we should be separating l10n files first?




Hi Theodore,

Thanks for speaking up.

On Sun, Nov 12, 2017 at 02:18:45PM -0500, Theodore Ts'o wrote:
> 1)  If people really want to make e2fsprogs non-essential, I'm not
> going to object seriously.  It's the downgrade of e2fsprogs from
> Priority: required to Priority: important which where things get
> super-exciting.

It's true that merely making e2fsprogs non-essential will not shrink
minbase. There are other chroot generators such as multistrap that
permit making smaller chroots though. From my pov, the important bit in
making e2fsprogs non-essential is to get the relevant dependencies in
place to figure out when it is safe to remove it. (See below.)

> 2) I'm at this point I'm not really enthuiastic to move lsattr out of
> e2fsprogs.  We are still adding new features to ext4, some of which
> will require new flags, and chattr/lsattr et.al. *were* originally
> designed to be only for ext 2/3/4.  Other file systems have decided to
> use the same ioctl, which is fine, but I've always considered
> chattr/lsattr to be an ext 2/3/4 utility first, and more generic file
> system utility second.  Moving lsattr out of e2fsprogs to some other
> package (e.g., util-linux) will make my kernel development much more
> inconvenient.
> 
> 3) Lsattr/chattr et.al depend on the e2fsprogs shared libraries, so
> moving them into a separate binary package isn't going to save as much
> space as you would like.  So it's not at all clear the complexity is
> worth it.

I'm not enthusiastic about moving lsattr either for precisely the reasons
you name.

> 4) If the real goal is reduce the size of minbase, there is a much
> more effective thing we can do first, or at least, in parallel.  And
> that is to move the l10n files to a separate foo-l10n package.  The
> last time I did this analysis was with Debian Jessie, but I don't
> think the numbers have changed that much.  Of the 201 MB i386 minbase
> chroot, 33MB, or over 16% can be found in /usr/local/locale.  The
> breakdown (using Debian Jessie numbers) are:

My goal here is a twofold shrinking. You can shrink the package count
and the installation size.

Reducing the package count lowers the complexity of the bootstrap
problem. If e2fsprogs (or anything else) can be moved to the native
phase, that's a win.

Using Debian for embedded typically requires moving beyond minbase.
Removing locales is typically done with --path-exclude or similar,
because it is mostly riskless. Following your proposal (from your next
reply) to simply remove binaries is not riskless, as anything might use
them (due to being essential). Removing a whole package is less risky as
apt will complain when you do something stupid.

So if you go beyond the locale and /usr/share/doc removal, e2fsprogs
suddenly looks like low hanging fruit after perl, but perl is much
harder to remove. In a sense, e2fsprogs might be the lowest hanging
fruit. (And that always depends on what the goal is.)

> Does this mean trying to get to Essential: no for e2fsprogs is a bad
> thing?  No, but if your goal is reduce the size of minbase for Debian,
> I just want to point out that there is **much** lower hanging fruit
> that folks might want to consider harvesting first.

For reducing e.g. docker images, your idea to tackle coreutils is a good
one. I leave that for others to work on and note that the second step
(after splitting coreutils and others) will become easier due to making
e2fsprogs non-essential.

I note that I tend to ignore the Priority field. ;)

Helmut