I thought it was United System Resources.
And I still don’t know what’s the point in separating /bin, /sbin, /usr/bin and /usr/sbin.
Also /mnt and /media
Or why it’s /root and not /home/root
Idk why I feel compelled to add this info, but / doesn’t have to be local as long as the necessary kernel modules for mounting it are available in the initrd or built into the kernel.
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.
The structure is changing, many distributions already are merging more and more of the duplicated subdirectories in /usr/ with the counterparts in / but it takes time to complete that and at the moment those subdirectories are often still there but as symlinks to be compatible with older software (and sysadmins).
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.
I know the distinction between /bin and /sbin, I just don’t know what purpose it serves.
Historically, /bin contained binaries that were needed before /usr was mounted during the boot process (/usr was usually on a networked drive).
Nowadays that’s obsolete, and most distros go ahead and merge the directories.
Instead of having one binary folder full of stuff that’s intended to be run with privilege access and non-privilege access, all the privileged stuff goes in sbin and you don’t even see it in your path as a regular user. It also means that access rights can be controlled at the folder level instead of the individual file level.
I thought it was United System Resources.
And I still don’t know what’s the point in separating /bin, /sbin, /usr/bin and /usr/sbin.
Also /mnt and /media
Or why it’s /root and not /home/root
Mostly historical reasons, /home was often a network mounted directory, but /root must be local.
And only regular users have their home in /home
Idk why I feel compelled to add this info, but / doesn’t have to be local as long as the necessary kernel modules for mounting it are available in the initrd or built into the kernel.
Yes, that is true. I was speaking in the context of very early Unix/Linux before initrd was a thing.
/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.
Something to do with hard-coded mounts in
/etc/fstabvs. dynamically-mounted removable media (USB drives etc.), I think.I’ve also seen autofs network automounts go in /net
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.
Is there a reason to keep this structure other than „we’ve always been doing it like that“/backwards compatibility?
The structure is changing, many distributions already are merging more and more of the duplicated subdirectories in /usr/ with the counterparts in / but it takes time to complete that and at the moment those subdirectories are often still there but as symlinks to be compatible with older software (and sysadmins).
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
/sbin are system binaries, eg root only stuff, dunno the rest but I would guess there are some historical reasons for the bin usr/bin separation
I know the distinction between /bin and /sbin, I just don’t know what purpose it serves.
Historically, /bin contained binaries that were needed before /usr was mounted during the boot process (/usr was usually on a networked drive).
Nowadays that’s obsolete, and most distros go ahead and merge the directories.
It’s easier to manage security that way.
Instead of having one binary folder full of stuff that’s intended to be run with privilege access and non-privilege access, all the privileged stuff goes in sbin and you don’t even see it in your path as a regular user. It also means that access rights can be controlled at the folder level instead of the individual file level.