RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that permits a system to take advantage of several hard drives as a single logical unit. Put simply, all of the drives are used as one and the information on all of them is identical. This type of a setup has 2 major advantages over using just a single drive to store data - the first one is redundancy, so if one drive doesn't work, the information will be accessed through 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 depending on how many drives are employed, whether reading and writing are both executed from all the drives concurrently, if 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 could differ.
RAID in Cloud Hosting
The drives that we use for storage with our revolutionary cloud hosting platform are not the classic HDDs, but fast solid-state drives (SSD). They function in RAID-Z - a special setup designed for the ZFS file system that we work with. All the content that you add to the cloud hosting account will be held on multiple disk drives and at least 1 shall be used as a parity disk. This is a special drive where a further bit is included to any content copied on it. In case a disk in the RAID stops working, it'll be changed with no service disturbances and the information will be recovered on the new drive by recalculating its bits thanks to the data on the parity disk along with that on the remaining disks. This is done to guarantee the integrity of the information and together with the real-time checksum verification that the ZFS file system performs on all drives, you'll never have to worry about the loss of any data no matter what.
RAID in Semi-dedicated Servers
The information uploaded to any semi-dedicated server account is saved on SSD drives that operate in RAID-Z. One of the drives in such a configuration is used for parity - each time data is copied on it, an additional bit is added. In case a disk turns out to be problematic, it will be taken out of the RAID without disturbing the work of the websites because the data will load from the remaining drives, and when a new drive is included, the information which will be duplicated on it will be a mix between the data on the parity disk and data saved on the other hard drives in the RAID. This is done in order to ensure that the data which is being cloned is correct, so once the new drive is rebuilt, it can be integrated into the RAID as a production one. This is an extra guarantee for the integrity of your information as the ZFS file system which runs on our cloud web hosting platform compares a special checksum of all of the copies of your files on the different drives so as to avoid any possibility of silent data corruption.
RAID in VPS Servers
The physical servers where we generate VPS server use high-speed SSD drives that will raise the speed of your sites considerably. The disk drives function in RAID to guarantee that you will not lose any data because of a power loss or a hardware malfunction. The production servers use multiple drives where the data is saved and one disk is used for parity i.e. one bit is added to all information copied on it, which makes it much easier to restore the site content without loss in the event a main drive breaks down. If you take advantage of our backup service, the data will be saved on an individual machine which uses standard hard-disk drives and although there isn't a parity one in this case, they are also in a RAID to guarantee that we will have a backup copy of your site content all of the time. With this kind of setup your data will always be safe as it will be available on multiple disk drives.