RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which permits a system to employ a number of hard drives as one single logical unit. Simply put, all drives are used as one and the information on all of them is the same. This type of a setup has two huge advantages over using just a single drive to save data - the first one is redundancy, so in case one drive fails, the information will be accessible through the others, and the second one is improved performance because the input/output, or reading/writing operations will be spread among multiple drives. You can find different RAID types in accordance with how many drives are employed, whether reading and writing are both executed from all of the drives concurrently, if data is written in blocks on one drive after another or is mirrored between drives in the same time, and so on. Depending on the exact setup, the fault tolerance and the performance may differ.
RAID in Shared Web Hosting
The disk drives that we employ for storage with our top-notch 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 work with. Any content that you add to the shared web hosting account will be saved on multiple drives and at least one shall be employed as a parity disk. This is a specific drive where an extra bit is included to any content copied on it. If a disk in the RAID stops working, it'll be changed without any service disruptions and the data will be recovered on the new drive by recalculating its bits thanks to the data on the parity disk along with that on the remaining disks. This is done to guarantee the integrity of the data and along with the real-time checksum validation which the ZFS file system runs on all drives, you will never have to worry about losing any information no matter what.
RAID in Semi-dedicated Hosting
The information 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. In case a disk happens to be flawed, it will be taken out of the RAID without interrupting the work of the Internet sites because the data will load from the rest of the drives, and when a new drive is added, the data which will be copied on it will be a mix between the data on the parity disk and data saved on the other hard drives in the RAID. This is done in order to guarantee that the data that is being copied is correct, so once the new drive is rebuilt, it can be incorporated into the RAID as a production one. This is an extra guarantee for the integrity of your information because the ZFS file system which runs on our cloud Internet hosting platform compares a special checksum of all copies of your files on the different drives in order to avoid any possibility of silent data corruption.
RAID in VPS Hosting
The SSD drives which we use on the physical machines where we create virtual private servers operate in RAID to ensure that any content which you upload will be available and intact all the time. At least one drive is used for parity - one bit of info is added to any data cloned on it. In the event that a main drive fails, it is changed and the information which will be cloned on it is calculated between the rest of the drives and the parity one. It's done this way to ensure that the right data is copied and that no file is corrupted because the new drive will be incorporated into the RAID afterwards. Also, we use hard disk drives operating in RAID on the backup servers, so if you add this upgrade to your VPS plan, you shall use an even more reliable Internet hosting service because your content will be available on multiple drives regardless of any sort of unpredicted hardware failure.