ZFS, which means Z File System, is an innovative file system which delivers top performance for websites and online programs. One of its main advantages is the real-time checksum comparison - each file features a checksum, or a digital fingerprint, and ZFS compares the checksums of all the files between the several hard drives functioning together in a RAID. If any file is damaged for some reason on one of the hard drives, it's restored from another drive with the correct checksum. Thus, the integrity of any file stored on a hosting server is ensured all of the time. ZFS also works considerably faster than other file systems, which allows backups to be generated much faster and without slowing down the general performance of the entire machine. Furthermore, ZFS does not have a set limit for the total amount of files which may be stored on a web server while all other file systems have some restriction which might cause problems at some point, especially for script programs that have a huge number of files.