ZFS, which means Z File System, is a progressive file system that offers better performance for web sites and online apps. One of its major advantages is the real-time checksum comparison - each and every file has a checksum, or a digital fingerprint, and ZFS compares the checksums of all files between the several hard drives operating together in a RAID. If any file is broken for some reason on one of the hard disks, it's restored from another travel with the correct checksum. As a result, the integrity of any file saved on a web server is ensured at all times. ZFS also functions considerably faster than other file systems, that permits backups to be produced much faster and without slowing down the general performance of the entire hosting server. Also, ZFS doesn't have a restriction for the total amount of files that can be stored on a web server while all other file systems have some restriction that could cause issues sooner or later, especially for script apps which have a lot of files.