RAID, or Redundant Array of Independent Disks, is a technology of saving data on several hard drives which operate together as a single logical unit. The drives can be physical or logical i.e. in the aforementioned case one single drive is divided into different ones through virtualization software. In any case, exactly the same information is stored on all the drives and the basic benefit of employing such a setup is that in the event that a drive fails, the data will remain available on the other ones. Having a RAID also improves the performance since the input and output operations will be spread among a number of drives. There are several kinds of RAID dependant upon how many drives are used, whether writing is done on all the drives in real time or just on a single one, and how the data is synchronized between the drives - whether it is written in blocks on one drive after another or it is mirrored from one on the others. All of these factors indicate that the fault tolerance as well as the performance between the different RAID types could differ.
RAID in Shared Web Hosting
The SSD drives that our cutting-edge cloud Internet hosting platform uses for storage function in RAID-Z. This type of RAID is created to work with the ZFS file system that runs on the platform and it uses the so-called parity disk - a specific drive where data kept on the other drives is copied with an extra bit added to it. In the event that one of the disks stops working, your sites will continue working from the other ones and as soon as we replace the problematic one, the data that will be duplicated on it will be rebuilt from what is stored on the rest of the drives as well as the information from the parity disk. This is performed so as to be able to recalculate the elements of each file properly and to authenticate 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 web hosting account in addition to the ZFS file system which compares a unique digital fingerprint for each file on all of the drives in real time.
RAID in Semi-dedicated Servers
In case you host your websites in a semi-dedicated server account from our company, all the content that you upload will be held on SSD drives which operate in RAID-Z. With this type of RAID, at least 1 of the hard drives is used for parity - when data is synced between the hard drives, an additional bit is added to it on the parity one. The purpose behind this is to ensure the integrity of the data that is duplicated to a brand new drive in case one of the drives in the RAID fails as the site content being copied on the new disk is recalculated from the information on the standard drives and on the parity one. Another advantage of RAID-Z is that even if a disk drive stops working, the system can easily switch to a different one instantly without service disruptions of any kind. RAID-Z adds an extra level of protection for the content that you upload on our cloud hosting platform together with the ZFS file system which uses unique checksums to authenticate the integrity of every single file.
RAID in VPS Servers
The SSD drives which we use on the physical machines where we generate VPS servers work in RAID to ensure that any content which you upload will be available and intact all the time. At least 1 drive is employed for parity - one bit of information is added to any data copied on it. If a main drive fails, it is replaced and the data that will be cloned on it is calculated between the remaining drives and the parity one. It's done this way to ensure that the right info is copied and that no file is corrupted as the new drive will be a part of the RAID afterwards. We also use hard disk drives working in RAID on the backup servers, so in case you add this upgrade to your VPS package, you will use an even more reliable hosting service as your content will be available on multiple drives irrespective of any kind of sudden hardware malfunction.