RAID, or Redundant Array of Independent Disks, is a technology for saving data on multiple hard drives which function together as one logical unit. The drives could be physical or logical i.e. in the second case one drive is split into separate ones via virtualization software. In either case, exactly the same info is kept on all drives and the key advantage of employing this type of a setup is that in the event that a drive fails, the data will remain available on the remaining ones. Using a RAID also enhances 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 performed on all of the drives in real time or just on a single one, and how the information is synced between the hard drives - whether it's written in blocks on one drive after another or it is mirrored from one on the others. All of these factors suggest that the error tolerance and the performance between the various RAID types could differ.
RAID in Hosting
All the content which you upload to your new hosting account will be placed on fast SSD drives that operate in RAID-Z. This setup is built to work with the ZFS file system which runs on our cloud Internet hosting platform and it adds another level of security for your site content on top of the real-time checksum verification which ZFS uses to ensure the integrity of the data. With RAID-Z, the data is stored on several disks and at least one is a parity disk - whenever info is recorded on it, an extra bit is added, so if any drive fails for some reason, the integrity of the info can be verified by recalculating its bits based on what is saved on the production hard drives and on the parity one. With RAID-Z, the functioning of our system won't be interrupted and it will continue working effectively until the problematic drive is changed and the data is synchronized on it.