RAID, or Redundant Array of Independent Disks, is a technology for keeping data on several hard disk drives which work together as one single logical unit. The drives can be physical or logical i.e. in the latter case one drive is divided into independent ones using virtualization software. Either way, the same data is stored on all of the drives and the main benefit of employing this type of a setup is that in the event that a drive stops working, the data will remain available on the other ones. Employing a RAID also enhances the overall performance because the input and output operations will be spread among a couple of drives. There are several kinds of RAID based on how many drives are used, whether writing is carried out on all drives in real time or just on one, and how the information is synchronized between the drives - whether it is written in blocks on one drive after another or all of it is mirrored from one on the others. All these factors imply that the error tolerance as well as the performance between the different RAID types may differ.
RAID in Cloud Web Hosting
The advanced cloud web hosting platform where all cloud web hosting accounts are made uses quick SSD drives rather than the classic HDDs, and they function in RAID-Z. With this setup, several hard drives work together and at least a single one is a dedicated parity disk. Basically, when data is written on the remaining drives, it is cloned on the parity one adding an extra bit. This is carried out for redundancy as even if some drive fails or falls out of the RAID for whatever reason, the information can be rebuilt and verified using the parity disk and the data stored on the other ones, therefore not a thing will be lost and there won't be any service interruptions. This is an additional level of protection for your data together with the advanced ZFS file system that uses checksums to guarantee that all of the data on our servers is undamaged and is not silently corrupted.