Linux

THREE WHOLE MEGABYTES

Me in 2024 holding a 4TB NVMe stick: Still not enough (it's never enough)

Mostly historical reasons, /home was often a network mounted directory, but /root must be local.

And only regular users have their home in /home

/home is often on a separate volume. You’d want root to be available in a maintenance situation where /home may not be mounted.

I don't recall the reasons for the addition but /media is newer than /mnt.

And I still don't know what's the point in separating /bin, /sbin, /usr/bin and /usr/sbin.

This goes back to the olden days when disk space was measured in kilo and megabytes. /sbin/ and /usr/sbin have the files needed to start a bare bone Unix/Linux system, so that you could boot from a 800kb floppy and mount all other directories via network or other storage devices as needed.

They hold "system binaries" meant for root user. It's not a hard distinction but many if not most Linux fundamentals have their roots in very early computing, mainframes, Bell and Xerox, and this good idea has been carried into the here&now. Not sure about the provenance of this one, but it makes sense. isn't /mnt /media different between distros? These aren't hard and fast rules - some distros choose to keep files elsewhere from the "standard".

/bin and /usr/bin, one is typically a symbolic link to another - they used to be stored on disks of different size, cost, and speed.

https://refspecs.linuxfoundation.org/FHS_3.0/fhs/ch03s16.html

https://unix.stackexchange.com/questions/5915/difference-between-bin-and-usr-bin

Not aware of any correct pictures, but I can tell you what's wrong with this one

• /usr: explaining it as "Unix System Resources" is a bit vague
• /bin: /bin is usually a symlink to /usr/bin
• /sbin: /sbin is usually a symlink to /usr/sbin, distros like Fedora are also looking into merging sbin into bin
• /opt: many, I'd say most, "add-on applications" put themselves in bin
• /media: /media is usually a symlink to /run/media, also weird to mention CD-ROMs when flash drives and other forms of storage get mounted here by default
• /mnt: i would disagree about the temporary part, as I mentioned before, stuff like flash drives are usually mounted in /run/media by default
• /root: the root user is usually not enabled on home systems
• /lib: /lib is usually a symlink to /usr/lib

I would also like the mention that the FHS standard wasn't designed to be elegant, well thought out system. It mainly documents how the filesystem has been traditionally laid out. I forget which folder(s), but once a new folder has been made just because the main hard drive in a developer's system filled up so they created a new folder named something different on a secondary hard drive.

For example, the new .config directory in the home directory.

I hope slowly but surely no program will ever dump its config(s) as ~/.xyz.conf (or even worse in a program specific ~/.thisapp/; The ~/.config/ scheme works as long as the programs don't repeat the bad way of dumping files as ~/.config/thisconfig.txt. (I'm looking at you kde folks..) A unique dir in .config directory should be mandatory.

If I ever need to shed some cruft accumulated over the years in ~/.config/ this would make it a lot easier.

According to this, it's been around since the 70's and was originally just a catch-all for files that didn't fit in the other default directories, but over time has come to be mostly used for config files. I assume it would cause utter mayhem to try and change the name now so I guess it just sticks. Someone suggested "Edit To Configure" as a backronym to try and make it make more sense if that helps anyone lol.

Is there a historical reason?

If you're asking that in anything Linux related, it's probably a Yes 99% of the time LMAO