RAID, or Redundant Array of Independent Disks, is a technology of keeping data on a number hard disk drives that function together as a single logical unit. The drives can be physical or logical i.e. in the second case one drive is divided into individual ones through virtualization software. In either case, the very same information is kept on all of the drives and the key advantage of using such a setup is that in case a drive fails, the data will still be available on the remaining ones. Employing a RAID also boosts the overall performance because the input and output operations will be spread among several drives. There are several types of RAID depending on how many hard drives are used, whether writing is carried out on all the drives in real time or just on one, and how the data is synced between the hard 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 fault tolerance as well as the performance between the various RAID types may differ.
RAID in Cloud Web Hosting
The hard disks that we employ for storage with our ground-breaking cloud hosting platform are not the traditional HDDs, but fast solid-state drives (SSD). They function in RAID-Z - a special setup intended for the ZFS file system that we employ. Any content that you add to the cloud web hosting account will be saved on multiple hard drives and at least one of them will be employed as a parity disk. This is a specific drive where an additional bit is added to any content copied on it. In case a disk in the RAID fails, it will be replaced with no service disturbances and the info will be recovered on the new drive by recalculating its bits using the data on the parity disk plus that on the other disks. This is done to guarantee the integrity of the info and along with the real-time checksum validation which the ZFS file system performs on all drives, you will never need to concern yourself with the loss of any info no matter what.