Redundant Array of Independent Disks, or RAID, is a method of keeping content on a number of hard drives at the same time. A RAID might be software or hardware depending on the HDDs which are used - physical or logical ones, yet what is common between them is the fact that they all function as a single unit where your information is kept. The top advantage of using a RAID is redundancy as the information on all drives shall be the same at all times, so even in the event that one of the drives fails for whatever reason, the data will still be available on the rest of the drives. The overall performance is also enhanced because the reading and writing processes will be split between a number of drives, so a single one can't be overloaded. There're different sorts of RAIDs where the performance and fault tolerance may vary based on the exact setup - whether information is written on all 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, and many others.
RAID in Website Hosting
The disk drives that we use for storage with our ground-breaking cloud hosting platform are not the traditional HDDs, but high-speed NVMes. They work in RAID-Z - a special setup designed for the ZFS file system which we work with. All of the content that you upload to the website hosting account will be kept on multiple hard drives and at least one of them will be used as a parity disk. This is a specific drive where an additional bit is added to any content copied on it. In the event that a disk in the RAID stops working, it will be replaced without service disruptions and the information will be rebuilt on the new drive by recalculating its bits thanks to the data on the parity disk plus that on the remaining disks. This is done so as to guarantee the integrity of the info and along with the real-time checksum authentication that the ZFS file system runs on all drives, you won't ever need to concern yourself with the loss of any information no matter what.
RAID in Semi-dedicated Hosting
The RAID type that we employ for the cloud hosting platform where your semi-dedicated hosting account shall be created is referred to as RAID-Z. What's different about it is that at least 1 of the disks is used as a parity drive. Simply put, whenever any kind of data is copied on this special hard drive, one more bit is included to it and in case a faulty disk is replaced, the info that will be copied on it is a combination of the data on the other hard disks in the RAID and that on the parity one. It's done this way to guarantee that the information is intact. Throughout this process, your websites will be functioning normally as RAID-Z allows for an entire drive to fail without any service disturbances and it simply uses one of the other ones as the main production drive. Using RAID-Z together with the ZFS file system which uses checksums to ensure that no data can get silently corrupted on our servers, you won't ever have to worry about the integrity of your files.
RAID in VPS Hosting
The NVMe drives that we use on the machines where we create virtual private servers work in RAID to ensure that any content that you upload will be available and intact all of the time. At least 1 drive is used for parity - one bit of info is added to any data cloned on it. If a main drive breaks down, it is changed and the information which will be cloned on it is calculated between the other drives and the parity one. This is done to ensure that the correct info is copied and that not a single file is corrupted as the new drive will be included in the RAID afterwards. Also, we use hard drives working in RAID on the backup servers, so in case you add this upgrade to your VPS package, you shall use an even more reliable hosting service since your content will be available on multiple drives regardless of any kind of unforeseen hardware failure.