Filesystem Hierarchy Standard

Definition:

• bin/: command binaries for commands, example /bin/ls is binaries for ls command
• boot/: system boot loader files
• dev/: Stores hardware and software device drivers. This directory maintains file system entries that represent the devices connected to the system (for example, the /dev/sda1 partition).
• etc/: system-wide config

  • etc>crontab

  • etc>fstab

  • etc>group

  • etc>httpd>conf>httpd.conf

  • etc>localtime

  • etc>ntp.conf

  • etc>passwd

  • etc>rsyslog.conf

  • rsyslog.d

    • etc>rsyslog.d>50-default.conf

  • etc>services

  • etc>shadow: user password reset, expire info

  • etc>skel: skeleton files for template, all new users have these files

  • ssh

    • etc>ssh>sshd_config

  • etc>sudoers

  • etc>systemd

  • etc>profile

  • share/

    • polkit-t/
      • rules.d with js files for local policies
    • polkit-1/
      • rules.d with js files for third-party policies

  • Red-hat etc>sysconfig>

  • Debian etc>network

• home/: user home dir, $HOME or ~
  • ~: for the current user
    • ~>.ssh>: stores files related to user’s ssh connection
      • ~>.ssh>config
• lib/: Stores shared program libraries required by the kernel, command-line utilities, and binaries.
• media/: media file such as CD-ROM
• mnt/: temporary mount
• opt/: Stores optional files of large software packages. These packages normally create a subdirectory bearing their name under the /opt directory and then place their files in the subdirectory. For example, the /opt/nessus subdirectory contains files for the Nessus vulnerability scanning program.
• proc/: a [Virtual File System] that represents continually updated kernel information to the user in a typical file format (for example, the /proc/mounts file).
• root/: home dir for root
• run/: run-time program data
• sbin/: Stores binaries that are used for completing the booting process and also the ones that are used by the root user. For example, the /sbin/ifconfig file is the binary for the ifconfig command that is used to manage network interfaces on the system
• srv/: site-specific data served by this system
• sys/: a Virtual File System (VFS), primarily stores information about devices. For example, /sys/block includes links to devices that are stored in various subdirectories under the /sys/ devices/ location, which presents a hierarchy of devices in the kernel.
  • sys>
• tmp/: temporary files
• usr/: unix system resources, read-only dir that stores small programs and file accessible to all users
  • bin/: include executable programs that can be executed by all users
  • local/: include custom build applications that are stored here by default
  • lib/: including object libraries and internal library that are needed by the executable programs
  • lib64/: same as lib/ but for 64 bit system
  • share/: Includes read-only architecture independent files. These files can be shared among different architectures of an operating system.
    • doc/
    • pokit-1/
      • actions/
        • .policy with XML files for defining actions
  • sbin/
• var/: files that is expected to continuously change, Examples include log files, printer spools, and some networking services’ configuration files.
  • var>log
    • var>log>auth.log for debian-based
      • var>log>secure for red hat-based
    • var>log>messages for debian-based
      • var>log>syslog for red hat-based
    • var>log>yum.log
    • var>log>httpd: httpd
    • lastlog: store last log in times, lastlog command
    • wtmp: store every login, logoff, last command