RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that enables a system to use several hard drives as one single logical unit. Put simply, all of the drives are used as one and the data on all of them is identical. This kind of a configuration has 2 key advantages over using just a single drive to keep data - the first is redundancy, so if one drive doesn't work, the information will be accessible from the others, and the second is improved performance since the input/output, or reading/writing operations will be distributed among different drives. There are different RAID types based on the number of drives are used, if reading and writing are both performed from all of the drives concurrently, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etcetera. Based on the exact setup, the fault tolerance and the performance vary.
RAID in Website Hosting
The SSD drives that our cutting-edge cloud web hosting platform employs for storage work in RAID-Z. This type of RAID is intended to work with the ZFS file system which runs on the platform and it uses the so-called parity disk - a special drive where data stored on the other drives is cloned with an extra bit added to it. If one of the disks stops functioning, your sites will continue working from the other ones and after we replace the bad one, the information which will be copied on it will be rebuilt from what is stored on the rest of the drives together with the data from the parity disk. This is done so as to be able to recalculate the elements of each and every file correctly and to validate the integrity of the information duplicated on the new drive. This is another level of security for the content which you upload to your website hosting
account together with the ZFS file system that analyzes a unique digital fingerprint for each file on all of the hard drives in real time.
RAID in Semi-dedicated Hosting
The RAID type that we employ for the cloud hosting platform where your semi-dedicated hosting
account shall be created is called RAID-Z. What's different about it is that at least one of the disks is used as a parity drive. Put simply, whenever any data is cloned on this particular hard drive, one more bit is added to it and in case a defective disk is changed, the info that will be duplicated on it is a combination of the data on the other hard disks in the RAID and that on the parity one. This is done to guarantee that the info is intact. During this process, your sites will be working normally because RAID-Z allows for an entire drive to fail without any service interruptions and it simply uses one of the other ones as the main production drive. Using 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 need to worry about the integrity of your files.