RAID, or Redundant Array of Independent Disks, is a technology for keeping data on a number hard disk drives which work together as a single logical unit. The drives can be physical or logical i.e. in the second case a single drive is divided into individual ones using virtualization software. In either case, the very same info is saved on all of the drives and the main benefit of employing this kind of a setup is that in the event that a drive stops working, the data will remain available on the other ones. Using a RAID also boosts the overall performance because the input and output operations will be spread among a few drives. There are several types of RAID based on how many drives are used, whether writing is done on all of the drives in real time or just on one, and how the info 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 of these factors indicate that the fault tolerance and the performance between the different RAID types may vary.
RAID in Shared Hosting
Any content which you upload to your new shared hosting account will be placed on quick SSD drives which work in RAID-Z. This configuration is built to use the ZFS file system that runs on our cloud hosting platform and it adds another level of security for your site content on top of the real-time checksum authentication which ZFS uses to guarantee the integrity of the data. With RAID-Z, the data is stored on a couple of disks and at least 1 is a parity disk - whenever data is recorded on it, an extra bit is added, so if any drive stops working for whatever reason, the integrity of the data can be verified by recalculating its bits based on what is stored on the production hard drives and on the parity one. With RAID-Z, the operation of our system won't be interrupted and it will continue operating effectively until the faulty drive is replaced and the information is synced on it.