RAID, which is short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that allows a system to use multiple hard drives as one single logical unit. Put simply, all of the drives are used as one and the info on all of them is identical. This kind of a setup has two huge advantages over using a single drive to keep data - the first one is redundancy, so in case one drive doesn't work, the information will be accessible through the remaining ones, and the second one is improved performance since the input/output, or reading/writing operations will be distributed among multiple drives. You can find different RAID types based on what amount of drives are used, whether reading and writing are both executed from all of the drives simultaneously, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etc. Determined by the particular setup, the error tolerance and the performance may differ.
RAID in Shared Hosting
The hard disks that we employ for storage with our top-notch cloud hosting platform are not the traditional HDDs, but high-speed solid-state drives (SSD). They work in RAID-Z - a special setup created for the ZFS file system which we employ. All the content that you add to your shared hosting
account will be stored on multiple drives and at least one of them will be employed as a parity disk. This is a special drive where an additional bit is added to any content copied on it. In the event that a disk in the RAID stops working, it'll be replaced without any service interruptions and the information will be recovered 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 ensure 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 worry about losing any info no matter what.
RAID in Semi-dedicated Hosting
The RAID type that we use for the cloud hosting platform where your semi-dedicated hosting
account will be created is referred to as RAID-Z. What is 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 copied on this particular hard drive, one more bit is included to it and in case a malfunctioning disk is replaced, the info that will be cloned on it is a combination of the data on the other hard disks in the RAID and that on the parity one. It's done this way to make sure that the data is intact. During this process, your sites will be up and running normally as RAID-Z makes it possible for an entire drive to fail without causing any service disruptions and it simply uses one of the remaining ones as the main production drive. Using RAID-Z together with the ZFS file system which uses checksums to warrant 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
If you employ one of our virtual private server
packages, any content which you upload will be kept on SSD drives that operate in RAID. At least a single drive is intended for parity to guarantee the integrity of the info. In simple terms, this is a special drive where information is copied with one bit added to it. In case a disk from the RAID stops functioning, your sites will continue working and when a new disk substitutes the flawed one, the bits of the data that will be duplicated on it are calculated using the healthy and the parity drives. That way, any probability of corrupting data during the process is prevented. We also employ conventional hard drives which operate in RAID for storing backup copies, so if you include this service to your VPS package, your content will be kept on multiple drives and you'll never need to worry about its integrity even in the event of multiple drive failures.