Redundant Array of Independent Disks, or RAID, is a method of storing content on multiple hard drives concurrently. A RAID could be software or hardware depending on the drives that are used - physical or logical ones, yet what’s common between them is the fact that they all function as one single unit where information is stored. The top advantage of using a RAID is redundancy since the data on all the drives will be exactly the same all of the time, so even in case one of the drives fails for whatever reason, the data will still be available on the other drives. The general performance is also better as the reading and writing processes will be split between different drives, so a single one won't be overloaded. There're different sorts of RAIDs where the functionality and fault tolerance may differ depending on the exact setup - whether info is written on all the drives in real time or it's written on a single drive and afterwards mirrored on another, what number of drives are used for the RAID, etc.
RAID in Cloud Hosting
All the content which you upload to your new cloud hosting account will be placed on fast 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 an additional level of protection for your website content in addition to the real-time checksum authentication which ZFS uses to ensure the integrity of the data. With RAID-Z, the data is stored on a couple of disks and at least one of them is a parity disk - whenever information is recorded on it, an additional bit is added, so in case any drive stops functioning for some reason, the stability of the information can be verified by recalculating its bits based on what is saved on the production disks and on the parity one. With RAID-Z, the functioning of our system will not be interrupted and it will continue working smoothly until the faulty drive is changed and the data is synchronized on it.