Redundant Array of Independent Disks, or RAID, is a way of keeping content on a number of hard disks concurrently. A RAID might be software or hardware based on the HDDs that are used - physical or logical ones, but what is common between them is the fact that they all work as one single unit where your information is stored. The key advantage of employing a RAID is redundancy because the data on all the drives is exactly the same all of the time, so even if a drive fails for whatever reason, the info will still be present on the rest of the drives. The overall performance will also improve since the reading and writing processes could be split between multiple drives, so a single one can't be overloaded. There're different sorts of RAIDs where the capabilities and fault tolerance may vary according to the particular setup - whether information is written on all the drives in real time or it is written on one drive and after that mirrored on another, what number of drives are used for the RAID, and so on.
RAID in Shared Hosting
The drives which we employ for storage with our ground-breaking cloud Internet hosting platform are not the classic HDDs, but high-speed solid-state drives (SSD). They operate in RAID-Z - a special setup developed for the ZFS file system which we employ. All the content that you add to the shared hosting account will be held on multiple hard drives and at least one shall be employed as a parity disk. This is a special drive where an extra bit is included to any content copied on it. In case a disk in the RAID fails, it'll be changed without service disturbances and the information 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 to guarantee the integrity of the data and together with the real-time checksum verification that the ZFS file system executes on all drives, you'll never need to worry about losing any information no matter what.
RAID in Semi-dedicated Servers
If you host your websites inside a semi-dedicated server account from our company, all of the content that you upload will be held on SSD drives which work in RAID-Z. With this kind of RAID, at least 1 of the hard disks is used for parity - when data is synchronized between the disks, an additional bit is added to it on the parity one. The purpose behind this is to guarantee the integrity of the info that is cloned to a brand new drive if one of the hard drives in the RAID fails since the content being copied on the new disk is recalculated from the information on the standard hard drives and on the parity one. An additional advantage of RAID-Z is the fact that even if a hard drive stops working, the system could switch to a different one immediately without service interruptions of any sort. RAID-Z adds an additional level of security for the content which you upload on our cloud web hosting platform together with the ZFS file system which uses unique checksums in order to authenticate the integrity of each file.
RAID in VPS Servers
The physical servers where we make VPS server use high-speed SSD drives which will boost the speed of your sites significantly. The hard disks operate in RAID to ensure that you won't lose any information as a result of a power loss or a hardware failure. The production servers employ multiple drives where the information is saved and one disk is used for parity i.e. one bit is added to all the info copied on it, which makes it much easier to recover the website content without loss in case a main drive fails. In case you pick our backup service, the info will be stored on an independent machine that uses standard hard-disk drives and although there is no parity one in this case, they are also in a RAID to guarantee that we will have a backup of your site content all of the time. With this type of configuration your info will always be safe because it will be available on multiple disk drives.