Redundant Array of Independent Disks, or RAID, is a way of keeping content on several hard disks simultaneously. A RAID can be software or hardware depending on the hard drives which are used - physical or logical ones, yet what is common between them is that they all work as a single unit where info is kept. The main advantage of employing a RAID is redundancy because the information on all of the drives is the same all of the time, so even if some drive fails for whatever reason, the information will still be present on the other drives. The general performance is enhanced as well because the reading and writing processes will be split between multiple drives, so a single one will not be overloaded. There're different types of RAIDs where the efficiency and fault tolerance may vary based on the exact setup - whether data is written on all of the drives real-time or it's written on one drive and afterwards mirrored on another, what number of drives are used for the RAID, and many others.
RAID in Shared Hosting
The SSD drives that our cutting-edge cloud Internet hosting platform uses for storage work in RAID-Z. This type of RAID is developed to work with the ZFS file system which runs on the platform and it works by using the so-called parity disk - a special drive where data located on the other drives is cloned with an additional bit added to it. In the event that one of the disks fails, your websites will continue working from the other ones and as soon as we replace the bad one, the info which will be duplicated on it will be recovered from what is stored on the remaining drives as well as the information from the parity disk. This is performed in order to be able to recalculate the bits of each file correctly and to validate the integrity of the data duplicated on the new drive. This is an additional level of security for the info you upload to your shared hosting account along with the ZFS file system which compares a unique digital fingerprint for each and every file on all drives in real time.
RAID in Semi-dedicated Servers
The info uploaded to any semi-dedicated server account is kept on SSD drives which operate 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. If a disk happens to be faulty, it will be removed from the RAID without disturbing the operation of the websites since the data will load from the other drives, and when a new drive is added, the data that will be cloned on it will be a blend between the information on the parity disk and data kept on the other hard drives in the RAID. This is done to guarantee that the information that is being copied is correct, so once the new drive is rebuilt, it can be integrated into the RAID as a production one. This is an additional guarantee for the integrity of your info because the ZFS file system which runs on our cloud Internet hosting platform compares a unique checksum of all copies of your files on the different drives to be able to avoid any possibility of silent data corruption.
RAID in VPS Servers
All VPS server accounts which our company provides are generated on physical servers which take advantage of SSD drives working in RAID. At least 1 drive is used for parity - one additional bit is added to the information duplicated on it and if a main disk fails, this bit makes it much easier to recalculate the bits of the files on the damaged hard disk so that the correct data is restored on the new drive added to the RAID. In the mean time, your Internet sites will remain online since all the info will still load from at least 1 more hard disk. In case you add routine backups to your VPS package, a copy of your information will be kept on standard hard disks that also work in RAID since we want to make sure that any type of site content you upload will be protected at all times. Using multiple hard drives in RAID for all main and backup servers enables us to offer fast and reliable hosting service.