Understanding Linux Filesystem Hierarchy and Key Directories

Core Characteristics of Linux Filesystem

  • All directories logically reside under the root directory "/"
  • Directory contents are organized by functional categories

Primary Directory Strutcure

/bin      Essential binary executables
/boot     Boot loader files and kernel images
/dev      Device files
/etc      System-wide configuration files
/home     User home directories
/lib      Shared library files
/mnt      Temporary mount points
/opt      Optional application packages
/proc     Virtual filesystem for process information
/usr      Secondary hierarchy for user programs
/tmp      Temporary files

# View structure with:
ls -la /
# Or:
tree -L 1 /

Critical Configuration Directories

/etc/sysconfig/network-scripts/ifcfg-eth0  Network interface config
/etc/resolv.conf                          DNS resolver config
/etc/hosts                                Hostname resolution
/etc/fstab                                Filesystem mounts
/etc/sysconfig/network                    Hostname configuration
/etc/init.d                               Service scripts
/etc/profile                             Global environment settings

User and System Configuration Files

/etc/passwd        User account information
/etc/shadow        Encrypted password data
/etc/group         Group definitions
/etc/sudoers       Privilege escalation rules
/etc/login.defs    Default login settings
/etc/syslog.conf   System logging configuration

Log and Variable Data Locations

/var/log/messages      System event logs
/var/log/secure        Authentication logs
/var/log/wtmp          Login records
/var/spool/cron        Scheduled tasks
/var/spool/mail        User mailboxes

System Information in /proc

/proc/cpuinfo       Processor details
/proc/meminfo       Memory statistics
/proc/loadavg       System load averages
/proc/version       Kernel version
/proc/devices       Available devices
/proc/filesystems   Supported filesystems

Additional Configuration Paths

/etc/X11            X Window System config
/etc/protocols      Network protocol definitions
/etc/host.conf      Name resolution order
/etc/hosts.allow    Access control rules

Tags: Linux filesystem directory-structure system-administration

Posted on Thu, 24 Sep 2026 16:17:42 +0000 by Wabin