Understanding the bin, sbin, usr/bin, usr/sbin split (2010)

Historical origins of the split

• Several comments note the layout is mostly historical inertia: early Unix had tiny, separate disks for /, /usr, later others, so binaries and libs were split by what lived on which spindle.
• /bin and /sbin were for tools needed to boot and fix the system; /usr/bin and /usr/sbin for everything after other filesystems were mounted.
• /etc originally meant “miscellaneous stuff”, including binaries; sbin appears later (likely BSD/System V) as a place to move “system” binaries out of /etc.
• There is disagreement over whether the “s” in sbin ever officially meant “static”; some recall that rationale emerging later rather than being original.

Initramfs and the relevance of /bin and /sbin

• With initrd/initramfs containing all drivers and tools needed to mount real filesystems, several argue /bin and /sbin are effectively obsolete.
• Others see initrd as a fragile, distro-specific kludge that can break boot if misbuilt, and would prefer a simpler model with more built-ins or fewer moving parts.
• Embedded-use fans like initramfs for bundling tiny installers or recovery environments.

Modern /usr merge and filesystem simplification

• Many major distros have done the “/usr merge”: all binaries under /usr/bin, with /bin, /sbin, /usr/sbin kept as symlinks to avoid breaking shebangs and hardcoded paths.
• Some see this as sensible modernization and easier network/shared mounting; critics view it as adding indirection instead of truly cleaning up legacy.

Roles of /usr/local, /opt, /var, /srv, etc.

• Common view:
  • /usr = distro/base system;
  • /usr/local = site- or admin-installed software following system layout;
  • /opt = self-contained or commercial packages with their own trees.
• Others argue this is confused on Linux, where there is no single “base system” in the BSD sense.
• Debate over /var: some think of it as expendable, others stress it’s for important writable data (DBs, mail queues, caches) vs /tmp / /var/tmp.
• /srv is liked by some as a home for service data (e.g. web roots), but many packages still default to /var.

Alternative layouts and package models

• Various projects are cited as attempts to escape legacy: GoboLinux (per-app dirs like /Programs/App/Version), NixOS/Guix (content-addressed, isolated store), TinyCore (mountable .tcz packages), sta.li, containerized formats (Flatpak, Snap, AppImages).
• These promise better isolation, parallel versions, and simpler dependency management, but are often non-mainstream or require learning new tools/languages.

Base system vs. “hodgepodge” and user-local trees

• There is a lively dispute over whether a Linux distro constitutes a coherent “base system” or merely a kernel plus replaceable packages.
• XDG’s $HOME/.local/... hierarchy is criticized as redundant with $HOME, but others appreciate the consistent, namespaced layout (e.g. .local/share).