RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that enables a system to take advantage of a number of hard drives as a single logical unit. Simply put, all the drives are used as one and the info on all of them is identical. This kind of a setup has two major advantages over using just a single drive to store data - the first one is redundancy, so in the event that one drive breaks down, the info will be accessible from the remaining ones, and the second one is better performance because the input/output, or reading/writing operations will be spread among several drives. You can find different RAID types depending on what number of drives are used, whether reading and writing are both handled from all drives concurrently, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etc. Determined by the particular setup, the error tolerance and the performance could differ.
RAID in Website Hosting
The drives which we use for storage with our state-of-the-art cloud hosting platform are not the traditional HDDs, but super fast solid-state drives (SSD). They work in RAID-Z - a special setup designed for the ZFS file system that we employ. All of the content that you add to the website hosting account will be stored on multiple disk drives and at least one of them will be used as a parity disk. This is a specific drive where an extra bit is included to any content copied on it. In the event that a disk in the RAID stops working, it'll be replaced without any service interruptions and the data will be recovered on the new drive by recalculating its bits using the data on the parity disk along with that on the remaining disks. This is done in order to ensure the integrity of the data and together with the real-time checksum authentication that the ZFS file system runs on all drives, you'll never need to concern yourself with losing any information no matter what.
RAID in Semi-dedicated Hosting
The data uploaded to any semi-dedicated hosting account is stored on SSD drives that function in RAID-Z. One of the drives in type of a configuration is used for parity - whenever data is copied on it, an extra bit is added. If a disk turns out to be problematic, it will be removed from the RAID without disturbing the functioning of the websites as the data will load from the remaining drives, and when a new drive is added, the data that will be duplicated on it will be a combination between the info on the parity disk and data saved on the other drives in the RAID. That is done so as to ensure that the info which is being cloned is accurate, so as soon as the new drive is rebuilt, it can be included in the RAID as a production one. This is an additional guarantee for the integrity of your data since the ZFS file system that runs on our cloud web hosting platform analyzes a unique checksum of all the copies of the files on the different drives to be able to avoid any probability of silent data corruption.
RAID in VPS Hosting
The physical servers where we make virtual private server employ extremely fast SSD drives which will increase the speed of your sites considerably. The hard disks function in RAID to make sure that you will not lose any info due to a power loss or a hardware breakdown. The production servers take advantage of multiple drives where the data is saved and one disk is used for parity i.e. one bit is added to all info copied on it, that makes it easier to restore the content without loss if a main drive breaks down. If you take advantage of our backup service, your data will be saved on an individual machine that uses standard hard-disk drives and although there's no parity one in this case, they are also in a RAID to ensure that we will have a backup of your content all the time. With this type of setup your information will always be safe since it will be available on several disk drives.