RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which enables a system to employ a number of hard drives as a single logical unit. Simply put, all of the drives are used as one and the data on all of them is the same. This kind of a configuration has two huge advantages over using just a single drive to keep data - the first one is redundancy, so if one drive doesn't work, the information will be accessible through the others, and the second one is better performance because the input/output, or reading/writing operations will be distributed among different drives. You can find different RAID types based on the number of drives are employed, whether reading and writing are both executed from all drives simultaneously, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etcetera. Determined by the exact setup, the error tolerance and the performance may differ.
RAID in Web Hosting
The hard drives that we employ for storage with our state-of-the-art cloud hosting platform are not the standard HDDs, but super fast solid-state drives (SSD). They work in RAID-Z - a special setup developed for the ZFS file system which we use. Any content that you add to your web hosting account will be stored on multiple hard disks and at least one will 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 fails, it'll be replaced without any service disruptions and the info will be rebuilt on the new drive by recalculating its bits using the data on the parity disk plus that on the other disks. This is done so as to guarantee the integrity of the data and along with the real-time checksum verification which the ZFS file system performs on all drives, you won't ever need to concern yourself with the loss of any info no matter what.
RAID in Semi-dedicated Hosting
The info uploaded to any semi-dedicated hosting account is saved on SSD drives which work in RAID-Z. One of the drives in type of a setup is used for parity - whenever data is cloned on it, an extra bit is added. In case a disk turns out to be faulty, it will be removed from the RAID without disturbing the operation of the Internet sites because the data will load from the other drives, and when a new drive is included, the data that will be duplicated on it will be a mix between the information on the parity disk and data kept on the other drives in the RAID. That is done to guarantee that the information that is being copied is accurate, so once the new drive is rebuilt, it could be included in the RAID as a production one. This is an extra warranty for the integrity of your information since the ZFS file system that runs on our cloud hosting platform analyzes a unique checksum of all copies of your files on the different drives in order to avoid any chance of silent data corruption.
All virtual private server accounts that we provide are generated on physical servers which employ SSD drives operating in RAID. At least 1 drive is intended for parity - one extra bit is included in the information copied on it and if a main disk breaks down, this bit makes it easier to recalculate the bits of the files on the failed drive so that the accurate info is recovered on the new drive included in the RAID. At the same time, your Internet sites will stay online since all the information will still load from at least 1 more disk drive. In case you add routine backups to your VPS plan, a copy of your info will be saved on standard hard disks that also function in RAID since we would like to make sure that any content you add will be safe and sound all the time. Employing multiple hard drives in RAID for all main and backup servers allows us to offer fast and reliable hosting service.