RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which allows a system to take advantage of a number of hard drives as a single logical unit. To put it differently, all the drives are used as one and the info on all of them is the same. This kind of a setup has 2 major advantages over using a single drive to keep data - the first is redundancy, so if one drive breaks down, the information will be accessed through the remaining ones, and the second one is better performance since the input/output, or reading/writing operations will be distributed among a number of drives. You can find different RAID types in accordance with what amount of drives are used, whether reading and writing are both performed from all drives simultaneously, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etcetera. Depending on the particular setup, the error tolerance and the performance may vary.
RAID in Hosting
The disk drives that we use for storage with our innovative cloud hosting platform are not the classic HDDs, but high-speed solid-state drives (SSD). They work in RAID-Z - a special setup intended for the ZFS file system which we employ. Any content that you upload to your hosting account will be held on multiple hard drives and at least 1 will be employed as a parity disk. This is a special drive where an additional bit is added to any content copied on it. If a disk in the RAID stops working, it will be replaced without service disturbances and the data will be rebuilt on the new drive by recalculating its bits using the data on the parity disk along with that on the remaining disks. This is done so as to guarantee the integrity of the data and together with the real-time checksum verification which the ZFS file system executes on all drives, you'll never need to concern yourself with the loss of any data no matter what.
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 named RAID-Z. What's different about it is that at least one of the disks is used as a parity drive. Simply put, whenever any kind of data is cloned on this special disk drive, one more bit is added to it and if a defective disk is replaced, the info which will be duplicated on it is a combination of the data on the remaining disk drives in the RAID and that on the parity one. This is done to ensure that your data is intact. During this process, your Internet sites will be working normally as RAID-Z makes it possible for an entire drive to fail without any service disruptions and it simply uses one of the remaining ones as the main production drive. Employing RAID-Z together with the ZFS file system that uses checksums to ensure that no data will get silently corrupted on our servers, you won't need to worry about the integrity of your files.