RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which permits a system to use many hard drives as a single logical unit. Put simply, all the drives are used as one and the information on all of them is the same. This kind of a configuration has 2 huge advantages over using a single drive to save data - the first one is redundancy, so if one drive breaks down, the data will be accessed through the others, and the second is improved performance as the input/output, or reading/writing operations will be distributed among multiple drives. You can find different RAID types depending on the number of drives are used, whether reading and writing are both done from all of the drives simultaneously, if data is written in blocks on one drive after another or is mirrored between drives in the same time, and many others. Based on the exact setup, the fault tolerance and the performance may differ.
RAID in Cloud Hosting
The state-of-the-art cloud hosting platform where all cloud hosting accounts are created employs fast SSD drives rather than the standard HDDs, and they work in RAID-Z. With this setup, numerous hard disks operate together and at least one of them is a dedicated parity disk. Put simply, when data is written on the rest of the drives, it is copied on the parity one adding an extra bit. This is done for redundancy as even in case some drive fails or falls out of the RAID for whatever reason, the info can be rebuilt and verified using the parity disk and the data recorded on the other ones, therefore absolutely nothing will be lost and there will not be any service interruptions. This is an additional level of protection for your data in addition to the state-of-the-art ZFS file system which uses checksums to guarantee that all data on our servers is intact and is not silently corrupted.
RAID in Semi-dedicated Servers
The data uploaded to any semi-dedicated server account is saved on SSD drives that work in RAID-Z. One of the drives in such a configuration is used for parity - each time data is cloned on it, an additional bit is added. If a disk happens to be faulty, it will be taken out of the RAID without interrupting the work of the websites since the data will load from the rest of the drives, and when a brand new drive is added, 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 drives in the RAID. This is done in order to guarantee that the info that is being copied is accurate, so once the new drive is rebuilt, it could be included in the RAID as a production one. This is an additional guarantee for the integrity of your data because the ZFS file system which runs on our cloud web hosting platform analyzes a special checksum of all copies of your files on the separate drives in order to avoid any probability of silent data corruption.
RAID in VPS Servers
The physical servers where we create VPS server work with extremely fast SSD drives which will increase the speed of your websites substantially. The hard disks function in RAID to ensure that you will not lose any information as a result of a power loss or a hardware breakdown. The production servers work with many different drives where the info is stored and one disk is used for parity i.e. one bit is added to all of the info copied on it, that makes it easier to restore the content without any loss in the event a main drive breaks down. In case you choose our backup service, the info will be saved on a separate machine that uses standard hard-disk drives and though there's no parity one in this case, they are also in a RAID to guarantee that we will have a backup of your website content at all times. With this particular setup your info will always be safe as it will be available on several drives.