Redundant Array of Independent Disks, or RAID, is a method of keeping content on several hard drives concurrently. A RAID can be software or hardware depending on the drives that are used - physical or logical ones, yet what is common between them is that they all operate as just a single unit where your information is kept. The main advantage of using a RAID is redundancy because the information on all of the drives shall be exactly the same at all times, so even if one of the drives fails for some reason, the information will still be available on the rest of the drives. The overall performance is also better because the reading and writing processes could be split between various drives, so a single one can't be overloaded. There are different kinds of RAIDs where the capabilities and fault tolerance could differ based on the specific setup - whether information is written on all drives real-time or it is written on one drive and then mirrored on another, what amount of drives are used for the RAID, etc.
RAID in Cloud Website Hosting
The disk drives that we use for storage with our state-of-the-art cloud Internet hosting platform are not the classic HDDs, but fast solid-state drives (SSD). They function in RAID-Z - a special setup designed for the ZFS file system which we use. All the content that you upload to the cloud website hosting account will be kept on multiple hard drives and at least 1 shall be employed as a parity disk. This is a special drive where an additional bit is added to any content copied on it. In case a disk in the RAID stops working, it'll be replaced with no service disruptions and the data will be rebuilt on the new drive by recalculating its bits thanks to the data on the parity disk along with that on the other disks. This is done to ensure the integrity of the info and together with the real-time checksum validation that the ZFS file system executes on all drives, you won't ever have to worry about the loss of any information no matter what.
RAID in Semi-dedicated Servers
The information uploaded to any semi-dedicated server account is kept on SSD drives which function in RAID-Z. One of the drives in this kind of a setup is used for parity - every time data is cloned on it, an additional bit is added. In case a disk turns out to be defective, it will be taken out of the RAID without disturbing the work of the websites since the data will load from the rest of the drives, and when a brand new drive is included, the data that will be duplicated on it will be a mix between the info on the parity disk and data stored on the other hard disks in the RAID. This is done to ensure that the information that is being duplicated is accurate, so the moment the new drive is rebuilt, it could be incorporated into the RAID as a production one. This is an extra guarantee for the integrity of your info because the ZFS file system which runs on our cloud Internet hosting platform analyzes a unique checksum of all the copies of the files on the different drives to be able to avoid any chance of silent data corruption.
RAID in VPS Servers
The physical servers where we make VPS server employ extremely fast SSD drives which will boost the speed of your websites significantly. The hard disks function in RAID to make sure that you won't lose any info as a result of a power loss or a hardware failure. The production servers employ a variety of drives where the data is saved and one disk is used for parity i.e. one bit is added to all of the information copied on it, that makes it much easier to restore the site content without any loss if a main drive stops working. If you pick our backup service, the data will be saved on an individual machine that uses standard hard-disk drives and even though there's no parity one in this case, they are also in a RAID to make sure that we will have a backup copy of your site content all of the time. With this configuration your information will always be safe since it will be available on many disk drives.