Redundant Array of Independent Disks, or RAID, is a way of saving content on several hard disks simultaneously. A RAID might be software or hardware based on the drives which are used - physical or logical ones, but what’s common between them is the fact that they all operate as a single unit where data is kept. The key advantage of employing a RAID is redundancy because the info on all the drives will be identical all of the time, so even in case one of the drives fails for some reason, the information will still be available on the rest of the drives. The general performance is enhanced as well as the reading and writing processes will be split between multiple drives, so a single one will never be overloaded. There're different types of RAIDs where the effectiveness and fault tolerance may differ based on the specific setup - whether data is written on all drives in real time or it is written on a single drive and afterwards mirrored on another, the number of drives are used for the RAID, etcetera.
RAID in Hosting
Our advanced cloud hosting platform where all hosting accounts are created uses quick SSD drives rather than the classic HDDs, and they function in RAID-Z. With this configuration, multiple hard drives function together and at least 1 is a dedicated parity disk. Put simply, when data is written on the other drives, it is duplicated on the parity one adding an extra bit. This is carried out for redundancy as even in case some drive fails or falls out of the RAID for some reason, the info can be rebuilt and verified using the parity disk and the data saved on the other ones, therefore nothing will be lost and there will be no service disorders. This is one more level of protection for your info in addition to the advanced ZFS file system which uses checksums to make sure that all of the data on our servers is undamaged and is not silently corrupted.