RAID, or Redundant Array of Independent Disks, is a technology of storing data on multiple hard disks that work together as one single logical unit. The drives can be physical or logical i.e. in the second case one drive is divided into independent ones via virtualization software. In either case, the same data is saved on all of the drives and the basic advantage of employing this kind of a setup is that in the event that a drive breaks down, the data shall still be available on the remaining ones. Employing a RAID also enhances 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 disks 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 drives - whether it's recorded in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors show that the fault tolerance as well as the performance between the various RAID types may differ.
RAID in Cloud Hosting
All the content that you upload to your new cloud hosting account will be held on quick SSD drives that work in RAID-Z. This setup is built to use the ZFS file system which runs on our cloud hosting platform and it adds another level of protection for your content in addition to the real-time checksum validation that ZFS uses to guarantee the integrity of the data. With RAID-Z, the data is saved on several disks and at least 1 is a parity disk - whenever information is written on it, an extra bit is added, so in case any drive stops functioning for some reason, the integrity of the information can be verified by recalculating its bits based on what is kept on the production hard disks and on the parity one. With RAID-Z, the operation of our system will never be interrupted and it will continue working effectively until the faulty drive is replaced and the information is synced on it.