RAID, or Redundant Array of Independent Disks, is a technology for storing data on a number hard drives that work together as one single logical unit. The drives could be physical or logical i.e. in the latter case one single drive is split into individual ones through virtualization software. Either way, identical info is kept on all the drives and the basic benefit of using such a setup is that in case a drive breaks down, the data will remain available on the remaining ones. Employing a RAID also improves the performance since the input and output operations will be spread among several drives. There are several kinds of RAID depending on how many drives are used, whether writing is done on all the drives in real time or just on a single one, and how the info is synchronized between the drives - whether it's written in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors imply that the error tolerance as well as the performance between the different RAID types may vary.
RAID in Shared Hosting
All the content which you upload to your new shared hosting account will be held on quick SSD drives that operate in RAID-Z. This setup is built to work with the ZFS file system that runs on our cloud Internet hosting platform and it adds one more level of security for your site content in addition to the real-time checksum validation which ZFS uses to ensure the integrity of the data. With RAID-Z, the data is saved on several disks and at least one of them is a parity disk - whenever info is recorded on it, an extra bit is added, so in the event that any drive fails for whatever reason, the integrity of the information can be verified by recalculating its bits in accordance with what is kept on the production disks and on the parity one. With RAID-Z, the operation of our system will never be interrupted and it'll continue working smoothly until the malfunctioning drive is replaced and the information is synced on it.