RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that enables a system to employ several hard drives as one single logical unit. In other words, all drives are used as one and the information on all of them is the same. Such a configuration has 2 major advantages over using a single drive to store data - the first is redundancy, so in case one drive stops working, the info will be accessible through the remaining ones, and the second is better performance because the input/output, or reading/writing operations will be distributed among several drives. You can find different RAID types depending on the number of drives are employed, whether reading and writing are both executed from all drives concurrently, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etc. Depending on the exact setup, the fault tolerance and the performance may vary.
RAID in Hosting
The SSD drives which our cutting-edge cloud web 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 uses the so-called parity disk - a specific drive where information located on the other drives is cloned with an extra bit added to it. In case one of the disks stops working, your websites shall continue working from the other ones and as soon as we replace the bad one, the data that will be duplicated on it will be rebuilt from what is stored on the other drives along with the data from the parity disk. This is performed in order to be able to recalculate the elements of every single file correctly and to validate the integrity of the data cloned on the new drive. This is one more level of security for the info which you upload to your hosting account in addition to the ZFS file system which analyzes a special digital fingerprint for each and every file on all of the hard drives in real time.
RAID in Semi-dedicated Servers
The RAID type which we employ for the cloud Internet hosting platform where your semi-dedicated server account will be created is named RAID-Z. What is different about it is that at least one of the disks is used as a parity drive. Put simply, whenever any kind of data is cloned on this particular drive, one more bit is added to it and if a defective disk is replaced, the data which will be copied on it is a mix of the data on the remaining hard disks in the RAID and that on the parity one. We do this to make sure that the info is intact. During this process, your Internet sites will be up and running normally as RAID-Z enables a whole drive to fail without causing any service disruptions and it simply works by using one of the remaining ones as the main production drive. Using RAID-Z together with the ZFS file system which uses checksums to guarantee that no data can get silently corrupted on our servers, you will never need to worry about the integrity of your files.
RAID in VPS Servers
The SSD drives that we use on the machines where we set up VPS servers function in RAID to make sure that any content that you upload will be available and intact all the time. At least one drive is employed for parity - one bit of data is added to any data cloned on it. In the event that a main drive stops working, it is changed and the data that will be copied on it is calculated between the rest of the drives and the parity one. It's done this way to make sure that the needed info is copied and that not a single file is corrupted because the new drive will be a part of the RAID afterwards. Also, we use hard drives working in RAID on the backup servers, so if you add this upgrade to your VPS package, you'll use an even more reliable web hosting service as your content will be available on multiple drives irrespective of any type of unpredicted hardware failure.