RAID, or Redundant Array of Independent Disks, is a technology of saving data on a number hard disk drives that function together as one single logical unit. The drives could be physical or logical i.e. in the latter case one drive is split into separate ones through virtualization software. In any case, identical data is kept on all drives and the basic benefit of using this kind of a setup is that in the event that a drive breaks down, the data will still be available on the other ones. Using a RAID also improves the performance since the input and output operations will be spread among a couple of drives. There are several types of RAID dependant upon how many hard drives are used, whether writing is performed on all drives in real time or just on one, and how the data is synced between the hard drives - whether it's written in blocks on one drive after another or it is mirrored from one on the others. These factors mean that the fault tolerance as well as the performance between the various RAID types can differ.
RAID in Cloud Web Hosting
All the content that you upload to your new cloud web hosting account will be placed on quick SSD drives which work in RAID-Z. This configuration is built to work with the ZFS file system which runs on our cloud web hosting platform and it adds another level of security for your site content in addition to the real-time checksum authentication that ZFS uses to ensure the integrity of the data. With RAID-Z, the data is saved on a couple of disks and at least one of them is a parity disk - whenever data is written on it, an additional bit is added, so if any drive fails for whatever reason, the integrity of the info can be verified by recalculating its bits based on what is stored on the production disks and on the parity one. With RAID-Z, the functioning of our system won't be interrupted and it will continue working flawlessly until the malfunctioning drive is changed and the information is synced on it.