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Kiergan

Member

Registered: 2017-05-31

Posts: 15  

Your thoughts on: TheCaseForTheUsrMerge

While Installing Mint on someone's laptop, I came across the recommendation to convert the system with USRmerge.
https://www.freedesktop.org/wiki/Softwa … eUsrMerge/

After reading, I was left with the question: Is this some new BS or is there really some merit in this idea?

Edit:
After a little digging:
https://lwn.net/Articles/773342/
This seems to go back for more than 10 years.

And I am now left with the idea that my initial feeling is probably right.

Anyone who wants to share their thoughts on this?

Edit:
Hmm, this seems to be a controversial topic.
Please let me know if it is not ok to have it posted here.

Edit2:
https://wiki.debian.org/UsrMerge says:
Will switching to a merged /usr be mandatory?
In February 2021, the Technical Committee has resolved that Debian 'bookworm' should support only the merged-usr root filesystem layout, dropping support for the non-merged-usr layout.

What will happen in Devuan concerning this?

Last edited by Kiergan (2022-06-08 07:56:35)

steve_v

Member

Registered: 2018-01-11

Posts: 381  

Re: Your thoughts on: TheCaseForTheUsrMerge

IMO, pointless change... Unless the point is to break systems with a minimal root FS and separate /usr (and likely runlevel 1 / single-user mode too). Admittedly those are probably few and far-between these days, but still, why break it?

Presumably the main argument for it is just the usual "vendor image" / "factory reset" / container-mania / unification One Linux BS from the Redhat/Gnome/systemd crowd.
Yawn.

As for Devuan, I expect it'll probably follow Debian. Removing systemd is enough work for a relatively small distro.
If it does, I'll probably seriously consider moving my remaining Devuan systems to Gentoo... Where 'split-usr' is just a (currently default) USE flag like 'systemd', 'pulseaudio', 'wayland' and all the zillions of other options.

Last edited by steve_v (2022-06-08 10:45:59)

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Head_on_a_Stick

Member

From: London

Registered: 2019-03-24

Posts: 3,125  

Website

Re: Your thoughts on: TheCaseForTheUsrMerge

is there really some merit in this idea?

Yes. I'm no expert but the reasoning given in the freedesktop.org and Debian wiki links seem sound.

What will happen in Devuan concerning this?

I would be surprised if they did not follow Debian's lead. Doing otherwise would require even more work than removing systemd.

Presumably the main argument for it is just the usual "vendor image" / "factory reset" / container-mania / unification One Linux BS from the Redhat/Gnome/systemd crowd.

Not really, although the changes are mainly driven by the container and embedded systems crowds. Graphical desktop users are such a pathetically small minority of Linux users that we are almost completely irrelevant to the people pushing commits and driving progress [sic].

I'll repost the FreeDesktop stuff here just for the record:

You are wondering why merging /bin, /sbin, /lib, /lib64 into their respective counterparts in /usr makes sense, and why distributions are pushing for it? You are wondering whether your own distribution should adopt the same change? Here are a few answers to these questions, with an emphasis on a compatibility point of view:

Compatibility: The Gist of It

    Improved compatibility with other Unixes/Linuxes in behavior: After the /usr merge all binaries become available in both /bin and /usr/bin, resp. both /sbin and /usr/sbin (simply because /bin becomes a symlink to /usr/bin, resp. /sbin to /usr/sbin). That means scripts/programs written for other Unixes or other Linuxes and ported to your distribution will no longer need fixing for the file system paths of the binaries called, which is otherwise a major source of frustration. /usr/bin and /bin (resp. /usr/sbin and /sbin) become entirely equivalent.
    Improved compatibility with other Unixes (in particular Solaris) in appearance: The primary commercial Unix implementation is nowadays Oracle Solaris. Solaris has already completed the same /usr merge in Solaris 11. By making the same change in Linux we minimize the difference towards the primary Unix implementation, thus easing portability from Solaris.
    Improved compatibility with GNU build systems: The biggest part of Linux software is built with GNU autoconf/automake (i.e. GNU autotools), which are unaware of the Linux-specific /usr split. Maintaining the /usr split requires non-trivial project-specific handling in the upstream build system, and in your distribution's packages. With the /usr merge, this work becomes unnecessary and porting packages to Linux becomes simpler.
    Improved compatibility with current upstream development: In order to minimize the delta from your Linux distribution to upstream development the /usr merge is key.

Compatibility: The Longer Version

A unified filesystem layout (as it results from the /usr merge) is more compatible with UNIX than Linux’ traditional split of /bin vs. /usr/bin. Unixes differ in where individual tools are installed, their locations in many cases are not defined at all and differ in the various Linux distributions. The /usr merge removes this difference in its entirety, and provides full compatibility with the locations of tools of any Unix via the symlink from /bin to /usr/bin.

I would also recommend reading Steve McVittie's comments on the matter:

https://lists.debian.org/debian-devel/2 … 00374.html

Trigger warning: he is a GNOME contributor

And I do have a question for the OP: why do you care if /bin/ is a symlink to /usr/bin/? What difference does it make to you?

Last edited by Head_on_a_Stick (2022-06-08 11:38:01)

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Brianna Ghey — Rest In Power

sgage

Member

Registered: 2016-12-01

Posts: 341  

Re: Your thoughts on: TheCaseForTheUsrMerge

Just for grins (and after backing up my system), I installed the usrmerge package just to see what would happen. Everything seems fine. I rebooted, everything still seems fine. I will report if anything comes up, but why would it?

User479

Member

From: Central USA

Registered: 2021-11-07

Posts: 25  

Re: Your thoughts on: TheCaseForTheUsrMerge

I did the usrmerge Feb 26 2021 when still on Debian Buster and have since been through an upgrande to Debian Bullseye and then a move to Devuan Chimaera, and have seen no problems.  The change seems inevitable given the momentum.

Apt and/or dpkg do seem to have obscure issues related to this and I think stuff can happen when installing a package built on a merged system on a non-merged system.

Edit 1: Read this when you've got a few hours to kill: https://lwn.net/SubscriberLink/890219/12423853bab9657d/

Last edited by User479 (2022-06-09 20:26:33)

Camtaf

Member

Registered: 2019-11-19

Posts: 436  

Re: Your thoughts on: TheCaseForTheUsrMerge

I presume, if one wants to, that you can still install a minimum system, whether this USRmerge exists or not, so don't really see any problems.

Unless I've missed something, the actual file system will remain the same, but just have links from /bin to /usr/bin, etc.

We used to install some software to /opt in the old days, has anyone missed that habit(?).

rolfie

Member

Registered: 2017-11-25

Posts: 1,172  

Re: Your thoughts on: TheCaseForTheUsrMerge

Just my 2 cents: I have approved the usrmerge option when being asked on all new installations that asked that question. I cannot see any reason to not agree. And I haven't seen any problems due to usrmerge in my small home network.

I have some SW in /opt, like FF, LO, TB, tor. All installed from external sources like tarballs from Mozilla, or the deb for a fresher LO version directly downloaded.

ralph.ronnquist

Administrator

From: Battery Point, Tasmania, AUS

Registered: 2016-11-30

Posts: 1,251  

Re: Your thoughts on: TheCaseForTheUsrMerge

Respectfully, these "works for me" anecdotes seem rather small-minded and useless, pretty much  like the whole idea itself.

Personally I'm in no way confused by having multiple directories with programs and libraries, and I imagine that the likelihood of confusing something or someone is larger with making this kind of change than not changing.

The idea is a matter of choice, and the main stigma is in the question of who should make the choice.

In many ways it's similar to that choice of excluding /sbin and /usr/sbin from non-root user's default setup; a choice which in my view is equally stupid.

But I don't make these choices. I merely learn to live with them.

EDX-0

Member

Registered: 2020-12-12

Posts: 81  

Re: Your thoughts on: TheCaseForTheUsrMerge

personally i think an approach like that of gobolinux is the better way for some aproaches specially in regards to libraries and compatibility, and combining it with a declarative package manager would really hit the nail, yes i know that is basically nixos but there's a lot of stuff about nixos i dislike in regards to it's architecture, like the reliance on systemd and the imutable base OS.

will later give the usrmerge package a test and see how it goes, like what can possibly go wrong?

Head_on_a_Stick

Member

From: London

Registered: 2019-03-24

Posts: 3,125  

Website

Re: Your thoughts on: TheCaseForTheUsrMerge

will later give the usrmerge package a test and see how it goes, like what can possibly go wrong?

Just FYI: the conversion is not reversible.

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Brianna Ghey — Rest In Power

Kiergan

Member

Registered: 2017-05-31

Posts: 15  

Re: Your thoughts on: TheCaseForTheUsrMerge

@Head_on_a_Stick
I do not know enough of Linux to be able to care or not care, it was just that it turned up at the install that I was doing and I had not come across it before.
Though veteran, perhaps, I am not an *nix-veteran.
Therefore, I thought to ask about it here.

And t.b.h. the fact that the article was linked below a systemd directory made me a little suspicious.

hunter0one

Member

Registered: 2021-12-31

Posts: 71  

Re: Your thoughts on: TheCaseForTheUsrMerge

I don't think UsrMerge hurts anything, it should make porting applications easier for everybody. For once the arguments that Lennart (I assume thats who wrote that freedesktop article) gave actually make sense here. When the option comes I will probably switch over.

User479

Member

From: Central USA

Registered: 2021-11-07

Posts: 25  

Re: Your thoughts on: TheCaseForTheUsrMerge

@hunter0one: The option has been here for a long time.

golinux

Administrator

Registered: 2016-11-25

Posts: 3,317  

Re: Your thoughts on: TheCaseForTheUsrMerge

Default in Devuan has been not to merge but Debian may close the door to the freedom to choose.

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hunter0one

Member

Registered: 2021-12-31

Posts: 71  

Re: Your thoughts on: TheCaseForTheUsrMerge

@User479: Just read that part in the Debian wiki and installed "usrmerge". :-)

I think that its great for Devuan to make it optional, after all we're all here because Debian likes to slowly force things.

User479

Member

From: Central USA

Registered: 2021-11-07

Posts: 25  

Re: Your thoughts on: TheCaseForTheUsrMerge

...Debian may close the door to the freedom to choose.

They are indeed doing that.  https://lists.debian.org/debian-devel/2022/09/msg00092.html