What Is a File Systems Table?

In computing, a file systems table (FSTAB) is a system file that contains information about the filesystems and their corresponding mount points on a Linux system. The FSTAB file is located in the /etc directory, and it’s read by the mount command during system startup to mount the filesystems specified in the file.

Fields

The FSTAB file is a plain-text file that consists of multiple lines, each representing a filesystem that needs to be mounted. Each line in the FSTAB file contains several fields that specify the filesystem’s attributes and mount options. The fields in the FSTAB file are separated by whitespace characters, such as tabs or spaces.

• The first field in the FSTAB file is the filesystem’s block device or network device. For local filesystems, this field specifies the device name or UUID, while for remote filesystems, this field specifies the network location and protocol.
• The second field specifies the mount point, which is the directory in the filesystem hierarchy where the filesystem will be mounted.
• The third field specifies the filesystem type, such as ext4, xfs, or nfs. The fourth field specifies the mount options, which control various aspects of the mount operation, such as read/write permissions, file ownership, and access control.
• The fifth field specifies whether the filesystem should be backed up or not. A value of 0 means that the filesystem should not be backed up, while a value of 1 means that it should be backed up.
• The sixth field specifies the mount order, which determines the order in which the filesystems are mounted.
• The seventh field specifies the filesystem check order, which determines the order in which the filesystems are checked for errors during system startup.

The FSTAB file is a critical system file that should be edited with caution. Any incorrect entries in the file can lead to system failures or data loss. It’s recommended to create a backup of the FSTAB file before making any changes and test the changes in a non-production environment.

Conclusion

In conclusion, the FSTAB file is a crucial system file that contains information about the filesystems and their corresponding mount points on a Linux system. It’s used by the mount command during system startup to mount the filesystems specified in the file. Understanding the structure and contents of the FSTAB file is essential for system administrators and developers who need to manage filesystems on Linux systems.