Redundant Array of Independent Disks, or RAID, is a way of saving content on several hard drives at the same time. A RAID can be software or hardware based on the HDDs which are used - physical or logical ones, however what is common between them is that they all work as a single unit where data is saved. The main advantage of using a RAID is redundancy as the info on all drives is the same all of the time, so even in the event that some drive fails for whatever reason, the information will still be available on the rest of the drives. The overall performance is also enhanced since the reading and writing processes can be split between a number of drives, so a single one won't be overloaded. There are different kinds of RAIDs where the capabilities and fault tolerance may vary depending on the specific setup - whether data is written on all drives in real time or it's written on one drive and then mirrored on another, what number of drives are used for the RAID, and so on.
RAID in Shared Web Hosting
Any content that you upload to your new shared web hosting account will be stored on quick SSD drives that function in RAID-Z. This setup is built to work with the ZFS file system which runs on our cloud web hosting platform and it adds one more level of security for your website content on top of the real-time checksum validation which ZFS uses to guarantee the integrity of the data. With RAID-Z, the info is saved on several disks and at least one of them is a parity disk - whenever data is written on it, an extra bit is added, so if any drive fails for some reason, the integrity of the data can be verified by recalculating its bits in accordance with what is stored on the production hard drives and on the parity one. With RAID-Z, the functioning of our system won't be interrupted and it'll continue functioning effectively until the faulty drive is changed and the information is synchronized on it.