RAID, or Redundant Array of Independent Disks, is a technology of keeping data on a number hard disk drives which operate together as a single logical unit. The drives can be physical or logical i.e. in the latter case one drive is split into separate ones using virtualization software. In either case, identical data is stored on all drives and the main benefit of using such a setup is that in case a drive stops working, the data will still be available on the remaining ones. Having a RAID also improves the overall performance since the input and output operations will be spread among a number of drives. There are several kinds of RAID depending on 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 synchronized between the drives - whether it is recorded in blocks on one drive after another or all of it is mirrored from one on the others. All these factors suggest that the error tolerance as well as the performance between the different RAID types can vary.
RAID in Cloud Web Hosting
The drives which we use for storage with our ground-breaking cloud web hosting platform are not the standard HDDs, but high-speed solid-state drives (SSD). They function in RAID-Z - a special setup designed for the ZFS file system which we use. Any content that you add to the cloud web hosting account will be kept on multiple drives and at least 1 will be used as a parity disk. This is a special drive where an additional bit is included to any content copied on it. In case a disk in the RAID stops functioning, it will be changed without any service disruptions and the information will be recovered on the new drive by recalculating its bits using the data on the parity disk along with that on the remaining disks. This is done so as to guarantee the integrity of the information and along with the real-time checksum authentication which the ZFS file system performs on all drives, you'll never need to be concerned about the loss of any data no matter what.