Linux Filesystem
From wikinotes
Unix is philosophically a little different from windows. Everything is a file. Your printer, speakers, mouse, keyboard etc are all represented within your filesystem.
Also, connected hard-drives are not exposed as drive letters, instead they are mounted to locations at or below the filesystem root (ex: '/').
Filesystems
A filesystem is the format used on a disk partition to record files.
Where windows typically uses fat32, or ntfs, linux normally uses ext4.
Locations
/boot
Boot partition. Contains Kernel, bootloader. /usr
/usr Programs, Libraries, ManPages, Unchanging files. (Designed so it can be stored remotely once all programs are installed) /var
/var Log Files, Spool (news, printers, mail), formatted manual pages, temporary files. User Specific. /home
User Docs
/bin
Binaries. For common cli commands ex: cp, mv, chmod /sbin
System Binaries. ex: ifconfig, getty, telinit /etc
/etc Config files and Executables specific to machine (ex: gdm3, xorg.conf, sudoers) /lib
libraries /dev
udev, devfs Devices exposed as files
/proc
linux procfs Illusionary filesystem that exists in memory (not on disk). Info about system /lost+found
Files saved during failures /net
Standard Mount point for remote file systems /opt
Extra Third Party Software
File Permissions
capacity/size
df -h # show all mounts, used/free space du -h <file> # show file size ncdu # interactive tool to navigate your filesystem, find largest files/directories
filesystem corruption
fsck (filesystem-check) checks the integrity of the filesystem, and attempts to repair it. only run this tool when a filesystem is unmounted