fstab
also: filesystem table
The /etc/fstab file is a configuration file that defines how disk partitions, block devices, and remote filesystems are mounted automatically when Linux boots.
/etc/fstab (filesystem table) contains entries that tell the Linux kernel and system utilities which filesystems to mount and where. Each line represents one filesystem with details about its location, mount point, type, and mount options.
A typical fstab entry has six fields: device identifier, mount point, filesystem type, mount options, dump flag, and fsck order. For example: /dev/sda1 / ext4 defaults 0 1 mounts the first partition as root using ext4 with default options, enables backups, and checks it first at boot.
The system reads fstab during startup to automatically mount filesystems without manual intervention. You can also use mount -a to mount all entries in fstab manually. This is essential for organizing storage, mounting network shares, and ensuring consistent filesystem configuration across reboots.