Redundant Array of Independent Disks, or RAID, is a way of storing content on multiple hard disks at the same time. A RAID might be software or hardware based on the drives which are used - physical or logical ones, however what’s common between them is the fact that they all perform as one single unit where data is stored. The biggest advantage of employing a RAID is redundancy as the information on all drives will be exactly the same all the time, so even in case one of the drives fails for some reason, the data will still be available on the other drives. The general performance is also enhanced since the reading and writing processes could be split between various drives, so a single one can't be overloaded. There're different sorts of RAIDs where the performance and fault tolerance can vary depending on the particular setup - whether info is written on all drives real-time or it is written on one drive and after that mirrored on another, the number of drives are used for the RAID, etc.
RAID in Cloud Hosting
The state-of-the-art cloud Internet hosting platform where all cloud hosting accounts are created employs fast SSD drives as an alternative to the standard HDDs, and they operate in RAID-Z. With this setup, several hard disk drives operate together and at least one of them is a dedicated parity disk. Put simply, when data is written on the other 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 some reason, the info can be rebuilt and verified using the parity disk and the data stored on the other ones, therefore not a single thing will be lost and there will be no service interruptions. This is an additional level of protection for your info along with the cutting-edge ZFS file system that uses checksums to ensure that all data on our servers is intact and is not silently corrupted.
RAID in Semi-dedicated Servers
The SSD drives that are used for storing any site content uploaded to the semi-dedicated server accounts which we provide work in RAID-Z. This is a special configuration where one or more disk drives are employed for parity i.e. the system will add an extra bit to any data cloned on this kind of a hard drive. In the event that a disk fails and is substituted with a new one, what info will be duplicated on the latter will be a mix calculated between the data on the remaining hard disks and that on the parity one. This is done to make sure that the data on the new drive shall be accurate. Throughout the procedure, the RAID will continue functioning normally and the faulty drive won't have an effect on the adequate operation of your sites in any way. Working with SSDs in RAID-Z is an excellent addition to the ZFS file system which runs on our state-of-the-art cloud platform with regards to preserving the integrity of your files as ZFS uses specific digital identifiers called checksums so as to avoid silent data corruption.
RAID in VPS Servers
The SSD drives which we use on the physical machines where we set up VPS servers function in RAID to make sure that any content you upload will be available and intact all the time. At least one drive is used for parity - one bit of data is added to any data copied on it. In the event that a main drive stops working, it is replaced and the information which will be duplicated on it is calculated between the remaining drives and the parity one. This is done to make sure that the needed info is copied and that not a single file is corrupted because the new drive will be used in the RAID afterwards. Also, we use hard disk drives functioning in RAID on the backup servers, so if you add this upgrade to your VPS plan, you will use an even more reliable hosting service because your content will be available on multiple drives regardless of any type of unpredicted hardware failure.