7 ms·

Debian pauses /usr merge file moves

41 points by gslin 3y ago

price 3y ago
A comment there on LWN, from a Debian developer, adds useful context: > [T]his is a misleading writeup of a Debian-internal announcement. One specific action that is mostly internal to Debian, which some developers wanted to push ahead with after the bookworm release, has been paused. > On a merged-/usr system (which will include all Debian 12 and Debian 13 systems, both new installations and upgrades), both /bin/cat and /usr/bin/cat exist, but dpkg is only aware of one of those paths (/bin/cat in this case); in dpkg jargon, the other is said to be an alias. The specific action that should not proceed until further notice is: swapping the path that dpkg considers to be canonical, for example from /bin/cat to /usr/bin/cat. In particular, the thing that this announcement pauses is only a shuffling of internal metadata. For users, /usr will already look merged either way. The other bit of context is that this "pause" comes as Debian approaches its next major release, and they expect to unpause it shortly after that.
- MuffinFlavored 3y ago
  > For users, /usr will already look merged either way. What's the motivation of moving /bin to /usr/bin? What is gained? What is lost?
  - saint_yossarian 3y ago
    https://www.freedesktop.org/wiki/Software/systemd/TheCaseForTheUsrMerge/ https://www.freedesktop.org/wiki/Software/systemd/TheCaseFor...
    - unethical_ban 3y ago
      I learned that Solaris is still used commercially. I remember buying "The OpenSolaris Bible" in 2008. Bad timing.
      - binarycrusader 3y ago
        The key missing context is: Solaris implemented the core part of the /usr merge 15 years ago already, and completed it with the introduction of Solaris 11 But more generally, Sun had a lot of smart people that cared deeply both about the *NIX Desktop and the general user experience. A trip through the PSARC archives[1] will show that things like the /usr merge were carefully considered and reasoned about. Some of those people are still working on Solaris today, although sadly, I'm no longer one of them. The Linux and BSD folks should take advantage of the good things that Sun left behind and carry them forward wherever possible. DISCLAIMER: I'm a former Solaris Principal Software Engineer so slightly biased ;) [1] https://illumos.org/opensolaris/ARChive/PSARC/ https://illumos.org/opensolaris/ARChive/PSARC/
        smcnally 3y ago
        Thank you for your service. Solaris felt more considered and reasoned than AIX and microchannel Linux I was learning in ~95 and so helped me learn more.
        unethical_ban 3y ago
        Ah, it's awesome you worked there. Thank you for context. My "bad timing" comment was in reference to Sun getting sold in 2010. As an IT focused college kid, I realized there wasn't much value in learning Solaris system administration. That doesn't mean it didn't have amazing things as an operating system!
  - MrStonedOne 3y ago
    Only having one key bin/ folder for hard coded paths. /usr/bin only existed because of fast small mainframe hard drives and slower larger hard drives. I don't understand why the direction is the way it is thou. getting rid of /usr/ seems like it would make more sense.
    - rblatz 3y ago
      I’m also confused why all system supplied data is in /usr instead of say /sys.
      - pilif 3y ago
        Because that potentially allows all distro-supplied files to live under one (eventually read-only) directory.
        Woodi 3y ago
        So, somebody imagined/wished that all distros will switch to /usr/* and them will ship / part ? :> I don't think so. Totally wrong direction. And init binary in /usr is complete braindeadness... Also MS behind anything means they are trying to get rid of your options, eg by complicating things into "enterprise level" and keep pushing windows as userware. But there is other possibility: minimal root that is easy to manage, switch, etc. etc. and rest of the system :)
        pfyra 3y ago
        > But there is other possibility: minimal root that is easy to manage, switch, etc. etc. and rest of the system :) Yeah, libostree ("git for operating systems binaries") benefits from merging /usr. It might even be a requirement to have merged /usr to be able to use it. https://en.m.wikipedia.org/wiki/OSTree https://en.m.wikipedia.org/wiki/OSTree
      - tivert 3y ago
        > I’m also confused why all system supplied data is in /usr instead of say /sys. Wasn't that basically a historical accident? IIRC in very early UNIX, "/usr" used to be like the modern "/home", but they happened to have a big disk for that mount and started putting system files there.
  - deleted 3y ago
    [deleted]
  - kevin_b_er 3y ago
    The motivation is because systemd is compelling them to change it. Systemd decides how Debian may operate, and decides how users, processes, and files work, not the Debian Technical Committee.
    - MBCook 3y ago
      It explicitly says in that link that systemd doesn’t need it and it’s beneficial to non-systemd distros.
      - kevin_b_er 3y ago
        That was then, and systemd is mandating it this year.
    - nubinetwork 3y ago
      FDO and systemd(et al) breaking things for everyone else as usual.
VWWHFSfQ 3y ago
Pray for all those scripts out there that assume /bin/sh or /bin/bash exists. Sounds like they only have a couple more years of error-free life
- josephcsible 3y ago
  Won't there be a symlink to keep those working?
- blueflow 3y ago
  There is no intent to remove the /bin symlink.
  - VWWHFSfQ 3y ago
    ah ok. well then whats the point of this
    - blueflow 3y ago
      Yes, this is why its a controversial thing.
    - masklinn 3y ago
      usr merge has been a topic for more than a decade, you can easily find articles on the subject in general, and for Debian in particular.
    - rektide 3y ago
      There's a bunch of compatibly reasons why this helps maintain portability across Unixes. But my favorite reasons for this are how much nicer it makes managing & switching between Linux images: > The merged directory /usr, containing almost the entire vendor-supplied operating system resources, offers us a number of new features regarding OS snapshotting and options for enterprise environments for network sharing or running multiple guests on one host. https://www.freedesktop.org/wiki/Software/systemd/TheCaseForTheUsrMerge/ https://www.freedesktop.org/wiki/Software/systemd/TheCaseFor... And indeed, with systemd one can boot a whole system from practically any unpopulated root mount with a /usr image mounted on it. Want to OS upgrade? Swap /usr & try it. /etc and /home and the other directories might have instance specific content, but the OS image is nicely set away & swappable in /usr. And one should be able to keep the same "instance" while swapping the image. It containerizes the OS image, separate-ish from the OS instancd, whereas before the OS was somewhat amorphously sprawled across multiple top level directories. It's a huge boon to manageability.
cout 3y ago
Sigh. I guess this means I can no longer keep my root image on a 1.44MB floppy and a separate /usr on an iomega Zip drive.
- mjg59 3y ago
  That remains a supported configuration, you just need an initramfs that mounts /usr before transitioning into the real /.
  - egberts1 3y ago
    nope. no room for initramfs on those kind of media.
    - mjg59 3y ago
      If you're already fitting a kernel on a 1.44MB floppy, you've got enough space to append a tiny cpio with a static binary that makes a few syscalls.
MuffinFlavored 3y ago
https://wiki.debian.org/UsrMerge https://wiki.debian.org/UsrMerge I don't get the proposed benefits?
- j16sdiz 3y ago
  There are no benefit. It's the systemd gangs don't want to support the standard directory hierarchy and force every distro to migrate. Debian is among the last to do these changes.
- TwoNineFive 3y ago
  Yep it's all systemd bunk. It reduces flexibility and promotes lock-in of systemd at the expense of everything else. It smells like a bunch of BS because it is.
deleted 3y ago
[deleted]
pierat 3y ago
Big note: /usr doesn't mean "user". It means "User Software Resources". I learned this from a good friend whose 70+ years old, and worked with Ritchie. My friend is also cited in K&R C. /usr/bin and /usr/sbin should have always been the place to put "user software resources". And we're finally getting back to what it was originally.
- fsh 3y ago
  /usr was the user directory before Thompson and Ritchie bought a new disk and mounted it as /home. The crazy names are really just a historical accident, not some smart acronyms.

41 points by gslin 3y ago

A comment there on LWN, from a Debian developer, adds useful context: > [T]his is a misleading writeup of a Debian-internal announcement. One specific action that is mostly internal to Debian, which some developers wanted to push ahead with after the bookworm release, has been paused. > On a merged-/usr system (which will include all Debian 12 and Debian 13 systems, both new installations and upgrades), both /bin/cat and /usr/bin/cat exist, but dpkg is only aware of one of those paths (/bin/cat in this case); in dpkg jargon, the other is said to be an alias. The specific action that should not proceed until further notice is: swapping the path that dpkg considers to be canonical, for example from /bin/cat to /usr/bin/cat. In particular, the thing that this announcement pauses is only a shuffling of internal metadata. For users, /usr will already look merged either way. The other bit of context is that this "pause" comes as Debian approaches its next major release, and they expect to unpause it shortly after that.

MuffinFlavored 3y ago
> For users, /usr will already look merged either way. What's the motivation of moving /bin to /usr/bin? What is gained? What is lost?
- saint_yossarian 3y ago
  https://www.freedesktop.org/wiki/Software/systemd/TheCaseForTheUsrMerge/ https://www.freedesktop.org/wiki/Software/systemd/TheCaseFor...
  - unethical_ban 3y ago
    I learned that Solaris is still used commercially. I remember buying "The OpenSolaris Bible" in 2008. Bad timing.
    - binarycrusader 3y ago
      The key missing context is: Solaris implemented the core part of the /usr merge 15 years ago already, and completed it with the introduction of Solaris 11 But more generally, Sun had a lot of smart people that cared deeply both about the *NIX Desktop and the general user experience. A trip through the PSARC archives[1] will show that things like the /usr merge were carefully considered and reasoned about. Some of those people are still working on Solaris today, although sadly, I'm no longer one of them. The Linux and BSD folks should take advantage of the good things that Sun left behind and carry them forward wherever possible. DISCLAIMER: I'm a former Solaris Principal Software Engineer so slightly biased ;) [1] https://illumos.org/opensolaris/ARChive/PSARC/ https://illumos.org/opensolaris/ARChive/PSARC/
      - smcnally 3y ago
        Thank you for your service. Solaris felt more considered and reasoned than AIX and microchannel Linux I was learning in ~95 and so helped me learn more.
      - unethical_ban 3y ago
        Ah, it's awesome you worked there. Thank you for context. My "bad timing" comment was in reference to Sun getting sold in 2010. As an IT focused college kid, I realized there wasn't much value in learning Solaris system administration. That doesn't mean it didn't have amazing things as an operating system!
- MrStonedOne 3y ago
  Only having one key bin/ folder for hard coded paths. /usr/bin only existed because of fast small mainframe hard drives and slower larger hard drives. I don't understand why the direction is the way it is thou. getting rid of /usr/ seems like it would make more sense.
  - rblatz 3y ago
    I’m also confused why all system supplied data is in /usr instead of say /sys.
    - pilif 3y ago
      Because that potentially allows all distro-supplied files to live under one (eventually read-only) directory.
      - Woodi 3y ago
        So, somebody imagined/wished that all distros will switch to /usr/* and them will ship / part ? :> I don't think so. Totally wrong direction. And init binary in /usr is complete braindeadness... Also MS behind anything means they are trying to get rid of your options, eg by complicating things into "enterprise level" and keep pushing windows as userware. But there is other possibility: minimal root that is easy to manage, switch, etc. etc. and rest of the system :)
        pfyra 3y ago
        > But there is other possibility: minimal root that is easy to manage, switch, etc. etc. and rest of the system :) Yeah, libostree ("git for operating systems binaries") benefits from merging /usr. It might even be a requirement to have merged /usr to be able to use it. https://en.m.wikipedia.org/wiki/OSTree https://en.m.wikipedia.org/wiki/OSTree
    - tivert 3y ago
      > I’m also confused why all system supplied data is in /usr instead of say /sys. Wasn't that basically a historical accident? IIRC in very early UNIX, "/usr" used to be like the modern "/home", but they happened to have a big disk for that mount and started putting system files there.
- deleted 3y ago
  [deleted]
- kevin_b_er 3y ago
  The motivation is because systemd is compelling them to change it. Systemd decides how Debian may operate, and decides how users, processes, and files work, not the Debian Technical Committee.
  - MBCook 3y ago
    It explicitly says in that link that systemd doesn’t need it and it’s beneficial to non-systemd distros.
    - kevin_b_er 3y ago
      That was then, and systemd is mandating it this year.
  - nubinetwork 3y ago
    FDO and systemd(et al) breaking things for everyone else as usual.

VWWHFSfQ 3y ago

Pray for all those scripts out there that assume /bin/sh or /bin/bash exists. Sounds like they only have a couple more years of error-free life

josephcsible 3y ago
Won't there be a symlink to keep those working?
blueflow 3y ago
There is no intent to remove the /bin symlink.
- VWWHFSfQ 3y ago
  ah ok. well then whats the point of this
  - blueflow 3y ago
    Yes, this is why its a controversial thing.
  - masklinn 3y ago
    usr merge has been a topic for more than a decade, you can easily find articles on the subject in general, and for Debian in particular.
  - rektide 3y ago
    There's a bunch of compatibly reasons why this helps maintain portability across Unixes. But my favorite reasons for this are how much nicer it makes managing & switching between Linux images: > The merged directory /usr, containing almost the entire vendor-supplied operating system resources, offers us a number of new features regarding OS snapshotting and options for enterprise environments for network sharing or running multiple guests on one host. https://www.freedesktop.org/wiki/Software/systemd/TheCaseForTheUsrMerge/ https://www.freedesktop.org/wiki/Software/systemd/TheCaseFor... And indeed, with systemd one can boot a whole system from practically any unpopulated root mount with a /usr image mounted on it. Want to OS upgrade? Swap /usr & try it. /etc and /home and the other directories might have instance specific content, but the OS image is nicely set away & swappable in /usr. And one should be able to keep the same "instance" while swapping the image. It containerizes the OS image, separate-ish from the OS instancd, whereas before the OS was somewhat amorphously sprawled across multiple top level directories. It's a huge boon to manageability.

cout 3y ago

Sigh. I guess this means I can no longer keep my root image on a 1.44MB floppy and a separate /usr on an iomega Zip drive.

mjg59 3y ago
That remains a supported configuration, you just need an initramfs that mounts /usr before transitioning into the real /.
- egberts1 3y ago
  nope. no room for initramfs on those kind of media.
  - mjg59 3y ago
    If you're already fitting a kernel on a 1.44MB floppy, you've got enough space to append a tiny cpio with a static binary that makes a few syscalls.

MuffinFlavored 3y ago

https://wiki.debian.org/UsrMerge https://wiki.debian.org/UsrMerge I don't get the proposed benefits?

j16sdiz 3y ago
There are no benefit. It's the systemd gangs don't want to support the standard directory hierarchy and force every distro to migrate. Debian is among the last to do these changes.
TwoNineFive 3y ago
Yep it's all systemd bunk. It reduces flexibility and promotes lock-in of systemd at the expense of everything else. It smells like a bunch of BS because it is.

deleted 3y ago

[deleted]

pierat 3y ago

Big note: /usr doesn't mean "user". It means "User Software Resources". I learned this from a good friend whose 70+ years old, and worked with Ritchie. My friend is also cited in K&R C. /usr/bin and /usr/sbin should have always been the place to put "user software resources". And we're finally getting back to what it was originally.

fsh 3y ago
/usr was the user directory before Thompson and Ritchie bought a new disk and mounted it as /home. The crazy names are really just a historical accident, not some smart acronyms.