RAID, or Redundant Array of Independent Disks, is a technology of keeping data on a number hard disk drives that operate together as a single logical unit. The drives could be physical or logical i.e. in the second case one single drive is split into independent ones via virtualization software. In either case, the same data is saved on all of the drives and the key advantage of employing such a setup is that in case a drive stops working, the data will remain available on the other ones. Using a RAID also boosts the overall performance because the input and output operations will be spread among several drives. There are several kinds of RAID based on how many hard drives are used, whether writing is carried out on all of the drives in real time or just on a single one, and how the data is synced between the hard drives - whether it is recorded in blocks on one drive after another or it is mirrored from one on the others. All these factors show that the fault tolerance as well as the performance between the various RAID types may differ.
RAID in Shared Hosting
The SSD drives that our cutting-edge cloud Internet hosting platform employs for storage work in RAID-Z. This type of RAID is created to work with the ZFS file system that runs on the platform and it employs the so-called parity disk - a specific drive where data stored on the other drives is copied with an extra bit added to it. In case one of the disks fails, your Internet sites shall continue working from the other ones and after we replace the problematic one, the info that will be duplicated on it will be rebuilt from what is stored on the other drives along with the info from the parity disk. This is performed in order to be able to recalculate the elements of each file adequately and to verify the integrity of the information duplicated on the new drive. This is another level of security for the content that you upload to your shared hosting
account together with the ZFS file system that compares a unique digital fingerprint for each file on all of the drives in real time.
RAID in Semi-dedicated Hosting
The RAID type which we use for the cloud Internet 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. Simply put, whenever any kind of data is duplicated on this specific drive, one more bit is added to it and in case a problematic disk is changed, the information that will be copied on it is a mix of the data on the remaining drives in the RAID and that on the parity one. It's done this way to ensure that the data is intact. During this process, your websites will be working normally as RAID-Z makes it possible for a whole drive to fail without causing any service interruptions and it simply uses one of the remaining ones as the main production drive. Using RAID-Z together with the ZFS file system that uses checksums to guarantee that no data will get silently corrupted on our servers, you will never need to worry about the integrity of your files.
RAID in VPS Hosting
If you use one of our virtual private server
packages, any content that you upload will be saved on SSD drives which work in RAID. At least a single drive is employed for parity to ensure the integrity of the information. In simple terms, this is a special drive where data is copied with one bit added to it. In the event that a disk from the RAID stops working, your sites will continue working and when a new disk substitutes the flawed one, the bits of the info that will be copied on it are calculated using the healthy and the parity drives. By doing this, any possibility of corrupting data throughout the process is averted. We also employ ordinary hard drives which work in RAID for storing backups, so if you add this service to your VPS plan, your website content will be stored on multiple drives and you'll never need to worry about its integrity even in the event of multiple drive failures.