directories under /

I was looking a little bit at what’s under / on my system. The list is:

bin   cdrom  etc   initrd  lost+found  mnt  plugins  root  srv    tmp  var
boot  dev    home  lib     media       opt  proc     sbin  sys    usr

The /mnt and /srv directories are empty. It seems to me that the /mnt dir is being replaced by the /media dir, so maybe at some point in the future it will disappear. The /srv dir is related to services… The /cdrom is a symbolic link to /media/cdrom.

The /bin, /lib, /sbin and /usr directories contain “the system” (even if the purpose of the secondary /usr tree escapes me).

The /etc directory contains all the system’s configuration files.

The /boot directory contains the boot loader and related files required at boot time. /initrd is empty.

/root is the home directory of the system administrator (root), while all other user directories are under /home.

The /dev, /proc and /sys directories are temporary filesystems dynamically generated at boot time (they exist in RAM, but not on the disk) containing system information. Further reading: sysfs, procfs and udev.

/opt is where additional applications are installed.

/lost+found is the “recycling bin”.

/tmp is a temporary filesystem (in RAM) containing temporary files created by the system or by programs.

/var contains “variable data files”. A good explanation of its purpose is:

/var is specified here in order to make it possible to mount /usr read-only.
Everything that once went into /usr that is written to during system operation
(as opposed to installation and software maintenance) must be in /var.

Finally, /plugins should not be there IMHO, it contains one subdirectory with one file, designer/libqwtplugin.so, from the Qt Widgets package I installed.

A helpful table is this one:

Directory	Description
bin	Essential command binaries
boot	Static files of the boot loader
dev	Device files
etc	Host-specific system configuration
lib	Essential shared libraries and kernel modules
media	Mount point for removeable media
mnt	Mount point for mounting a filesystem temporarily
opt	Add-on application software packages
sbin	Essential system binaries
srv	Data for services provided by this system
tmp	Temporary files
usr	Secondary hierarchy
var	Variable data

Reference: pathname.com

~ by azimout on June 5, 2008.