RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that allows a system to take advantage of several hard drives as one single logical unit. Put simply, all the drives are used as one and the info on all of them is the same. This type of a setup has 2 huge advantages over using a single drive to save data - the first one is redundancy, so if one drive breaks down, the info 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 multiple drives. You can find different RAID types depending on what amount of drives are used, whether reading and writing are both handled from all the drives simultaneously, 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 error tolerance and the performance vary.
RAID in Hosting
The drives which we employ for storage with our outstanding cloud web hosting platform are not the classic HDDs, but super fast solid-state drives (SSD). They work in RAID-Z - a special setup intended for the ZFS file system which we use. Any content that you add to your hosting account will be saved on multiple drives and at least one of them shall be employed as a parity disk. This is a special drive where an additional bit is included to any content copied on it. If a disk in the RAID stops functioning, it'll be replaced without any service disruptions and the info will be recovered on the new drive by recalculating its bits using the data on the parity disk plus that on the remaining disks. This is done in order to ensure the integrity of the information and together with the real-time checksum validation that the ZFS file system performs on all drives, you'll never need to be concerned about the loss of any info no matter what.
RAID in Semi-dedicated Hosting
The information uploaded to any semi-dedicated hosting account is stored on SSD drives that operate in RAID-Z. One of the drives in type of a setup is used for parity - each time data is copied on it, an extra bit is added. If a disk happens to be problematic, it will be removed from the RAID without disturbing the functioning of the Internet sites since the data will load from the other drives, and when a brand new drive is added, the information that will be cloned on it will be a combination between the information on the parity disk and data kept on the other hard drives in the RAID. This is done in order to ensure that the info which is being duplicated is accurate, so once the new drive is rebuilt, it could be integrated into the RAID as a production one. This is an extra guarantee for the integrity of your data since the ZFS file system which runs on our cloud Internet hosting platform analyzes a special checksum of all of the copies of the files on the different drives so as to avoid any chance of silent data corruption.
RAID in VPS Hosting
In case you use one of our virtual private server plans, any content which you upload will be stored on SSD drives which function in RAID. At least 1 drive is used for parity so as to guarantee the integrity of your info. In simple terms, this is a special drive where info is copied with one bit added to it. In case a disk in the RAID fails, your sites will continue working and when a new disk substitutes the faulty one, the bits of the info that will be duplicated on it are calculated using the healthy and the parity drives. By doing this, any possibility of corrupting data throughout the process is prevented. We also use ordinary hard drives which work in RAID for storing backups, so in case you include this service to your VPS package, your website content will be saved on multiple drives and you won't ever have to worry about its integrity even in the event of multiple drive failures.