RAID, or Redundant Array of Independent Disks, is a technology for saving data on multiple hard drives which function together as one logical unit. The drives can be physical or logical i.e. in the latter case one drive is split into different ones through virtualization software. In any case, identical information is kept on all the drives and the basic advantage of using this type of a setup is that if a drive fails, the data shall still be available on the other ones. Having a RAID also improves the overall performance because the input and output operations will be spread among a couple of drives. There are several types of RAID depending on how many drives are used, whether writing is performed on all the drives in real time or just on a single one, and how the info is synced between the drives - whether it's recorded in blocks on one drive after another or all of it is mirrored from one on the others. All these factors show that the fault tolerance as well as the performance between the different RAID types could differ.
RAID in Shared Hosting
The SSD drives which our cutting-edge cloud Internet hosting platform uses for storage function in RAID-Z. This kind of RAID is intended to work with the ZFS file system that runs on the platform and it takes advantage of the so-called parity disk - a specific drive where info stored on the other drives is copied with an additional bit added to it. In case one of the disks fails, your websites shall continue working from the other ones and once we replace the problematic one, the information that will be copied on it will be rebuilt from what is stored on the rest of the drives together with the info from the parity disk. This is done in order to be able to recalculate the bits of each file correctly and to verify the integrity of the info cloned on the new drive. This is an additional level of security for the information you upload to your shared hosting
account along with the ZFS file system which analyzes a special digital fingerprint for each and every file on all the drives in real time.
RAID in Semi-dedicated Hosting
The RAID type which we employ for the cloud web hosting platform where your semi-dedicated hosting
account shall be created is referred to as RAID-Z. What's different about it is that at least one of the disks is employed as a parity drive. Put simply, whenever any kind of data is cloned on this particular hard drive, one more bit is included to it and if a problematic disk is replaced, the info that will be copied on it is a mix of the data on the other disk drives in the RAID and that on the parity one. This is done to make sure that the data is intact. Throughout this process, your sites will be functioning normally as RAID-Z makes it possible for a whole drive to fail without causing any service disruptions and it simply works by using one of the other ones as the main production drive. Employing RAID-Z together with the ZFS file system that 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 Hosting
In case you employ one of our virtual private server
plans, any content that you upload will be kept on SSD drives that operate in RAID. At least a single drive is employed for parity to guarantee the integrity of your information. In simple terms, this is a special drive where information is copied with one bit added to it. In the event that a disk part of the RAID fails, your sites will continue working and when a new disk replaces the malfunctioning one, the bits of the information that will be cloned on it are calculated using the healthy and the parity drives. By doing this, any chance of corrupting data during the process is averted. We also use regular hard disks which function in RAID for storing backups, so in case you add this service to your VPS package, your content will be saved on multiple drives and you will never need to worry about its integrity even in the event of multiple drive failures.