7.5. Creating Directories

It is time to create the full directory structure in the LFS file system.



Some of the directories mentioned in this section may have already been created earlier with explicit instructions, or when installing some packages. They are repeated below for completeness.

Create some root-level directories that are not in the limited set required in the previous chapters by issuing the following command:

mkdir -pv /{boot,home,mnt,opt,srv}

Create the required set of subdirectories below the root-level by issuing the following commands:

mkdir -pv /etc/{opt,sysconfig}
mkdir -pv /lib/firmware
mkdir -pv /media/{floppy,cdrom}
mkdir -pv /usr/{,local/}{include,src}
mkdir -pv /usr/local/{bin,lib,sbin}
mkdir -pv /usr/{,local/}share/{color,dict,doc,info,locale,man}
mkdir -pv /usr/{,local/}share/{misc,terminfo,zoneinfo}
mkdir -pv /usr/{,local/}share/man/man{1..8}
mkdir -pv /var/{cache,local,log,mail,opt,spool}
mkdir -pv /var/lib/{color,misc,locate}

ln -sfv /run /var/run
ln -sfv /run/lock /var/lock

install -dv -m 0750 /root
install -dv -m 1777 /tmp /var/tmp

Directories are, by default, created with permission mode 755, but this is not desirable everywhere. In the commands above, two changes are made—one to the home directory of user root, and another to the directories for temporary files.

The first mode change ensures that not just anybody can enter the /root directory—just like a normal user would do with his or her own home directory. The second mode change makes sure that any user can write to the /tmp and /var/tmp directories, but cannot remove another user's files from them. The latter is prohibited by the so-called sticky bit, the highest bit (1) in the 1777 bit mask.

7.5.1. FHS Compliance Note

This directory tree is based on the Filesystem Hierarchy Standard (FHS) (available at https://refspecs.linuxfoundation.org/fhs.shtml). The FHS also specifies the optional existence of additional directories such as /usr/local/games and /usr/share/games. In LFS, we create only the directories that are really necessary. However, feel free to create more directories, if you wish.



The FHS does not mandate the existence of the directory /usr/lib64, and the LFS editors have decided not to use it. For the instructions in LFS and BLFS to work correctly, it is imperative that this directory be non-existent. From time to time you should verify that it does not exist, because it is easy to create it inadvertently, and this will probably break your system.