Redundant Array of Independent Disks, or RAID, is a way of saving content on a number of hard disk drives simultaneously. A RAID might be software or hardware based on the hard drives which are used - physical or logical ones, however what’s common between them is that they all work as a single unit where info is saved. The biggest advantage of using a RAID is redundancy because the data on all of the drives will be the same at all times, so even in case one of the drives fails for whatever reason, the data will still be present on the rest of the drives. The general performance is enhanced as well since the reading and writing processes could be split between multiple drives, so a single one won't be overloaded. There are different types of RAIDs where the functionality and fault tolerance can vary according to the exact setup - whether data is written on all the drives real-time or it is written on one drive and afterwards mirrored on another, the number of drives are used for the RAID, etc.
RAID in Shared Hosting
The SSD drives that our cutting-edge cloud web hosting platform employs for storage operate in RAID-Z. This sort of RAID is created to work with the ZFS file system which runs on the platform and it works by using the so-called parity disk - a special drive where info stored on the other drives is cloned with an extra bit added to it. If one of the disks stops functioning, your Internet sites shall continue working from the other ones and after we replace the bad one, the data that will be copied on it will be rebuilt from what is stored on the other drives along with the data from the parity disk. This is done so as to be able to recalculate the elements of every file properly and to verify the integrity of the data copied on the new drive. This is another level of security for the information you upload to your shared hosting account along with the ZFS file system which compares a special digital fingerprint for each file on all the hard drives in real time.