RAID, or Redundant Array of Independent Disks, is a technology for saving data on several hard disks that work together as one single logical unit. The drives could be physical or logical i.e. in the latter case one single drive is split into separate ones using virtualization software. In any case, the same info is saved on all of the drives and the main advantage of employing this type of a setup is that if a drive fails, the data will still be available on the remaining ones. Using a RAID also enhances the performance since the input and output operations will be spread among several drives. There are several types of RAID depending on how many hard disks are used, whether writing is performed on all drives in real time or just on a single one, and how the info is synchronized between the hard drives - whether it's recorded in blocks on one drive after another or it is mirrored from one on the others. These factors show that the error tolerance as well as the performance between the different RAID types could differ.
RAID in Shared Hosting
The SSD drives that our cutting-edge cloud Internet hosting platform employs for storage work in RAID-Z. This sort 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 specific drive where info kept on the other drives is copied with an extra bit added to it. In case one of the disks stops working, your websites will continue working from the other ones and after we replace the problematic one, the data that will be copied on it will be rebuilt from what is stored on the rest of the drives along with the info from the parity disk. This is performed in order to be able to recalculate the bits of each file properly and to confirm the integrity of the info copied on the new drive. This is an additional level of security for the info which you upload to your shared hosting account along with the ZFS file system which analyzes a unique digital fingerprint for every single file on all the hard drives in real time.
RAID in Semi-dedicated Hosting
The RAID type that we employ for the cloud web hosting platform where your semi-dedicated hosting account shall be created is named RAID-Z. What is different about it is that at least one of the disks is employed as a parity drive. Put simply, whenever any data is duplicated on this specific drive, one more bit is included to it and if a problematic disk is changed, the data that will be copied on it is a combination of the data on the remaining hard disks in the RAID and that on the parity one. It's done this way to ensure that the info is intact. During this process, your websites will be functioning normally as RAID-Z makes it possible for a whole drive to fail without service disruptions and it simply uses one of the other ones as the main production drive. Employing RAID-Z together with the ZFS file system which uses checksums to ensure that no data can get silently corrupted on our servers, you won't have to worry about the integrity of your files.
RAID in VPS Web Hosting
The physical servers where we generate virtual private server use quick SSD drives that will boost the speed of your websites substantially. The hard disks work in RAID to ensure that you will not lose any information due to a power loss or a hardware breakdown. The production servers use a variety of drives where the data is kept and one disk is used for parity i.e. one bit is added to all the information copied on it, that makes it much easier to restore the site content without loss in case a main drive stops working. If you take advantage of our backup service, your data will be stored on an independent machine that uses standard hard-disk drives and though there is no parity one in this case, they are also in a RAID to ensure that we will have a backup of your website content all of the time. With this configuration your data will always be safe because it will be available on multiple disk drives.