RAID, or Redundant Array of Independent Disks, is a technology for keeping data on multiple hard drives that operate together as one single logical unit. The drives can be physical or logical i.e. in the latter case a single drive is divided into independent ones through virtualization software. In either case, the very same data is kept on all of the drives and the basic advantage of using this kind of a setup is that in the event that a drive stops working, the data will remain available on the remaining ones. Employing a RAID also boosts the overall performance since the input and output operations will be spread among several drives. There are several kinds of RAID based on how many hard drives are used, whether writing is done on all drives in real time or just on a single one, and how the info is synced between the hard drives - whether it's recorded in blocks on one drive after another or all of it is mirrored from one on the others. All these factors show that the fault tolerance as well as the performance between the various RAID types may vary.
RAID in Cloud Web Hosting
The hard disks which we employ for storage with our ground-breaking cloud Internet hosting platform are not the classic HDDs, but quick solid-state drives (SSD). They function in RAID-Z - a special setup developed for the ZFS file system that we work with. All of the content that you add to the cloud web hosting account will be held on multiple drives and at least one will be employed as a parity disk. This is a special drive where a further bit is added to any content copied on it. In case a disk in the RAID fails, it will be replaced without service interruptions and the information will be rebuilt on the new drive by recalculating its bits thanks to the data on the parity disk plus that on the remaining disks. This is done in order to ensure the integrity of the info and along with the real-time checksum verification that the ZFS file system executes on all drives, you won't ever need to concern yourself with losing any info no matter what.