Redundant Array of Independent Disks, or RAID, is a method of keeping content on several hard disks at the same time. A RAID could be software or hardware depending on the hard drives that are used - physical or logical ones, still what is common between them is that they all perform as one single unit where information is stored. The main advantage of using a RAID is redundancy since the information on all drives shall be the same all of the time, so even if one of the drives fails for whatever reason, the data will still be available on the other drives. The overall performance is also enhanced since the reading and writing processes can be split between multiple drives, so a single one can't be overloaded. There are different sorts of RAIDs where the functionality and fault tolerance may vary based on the exact setup - whether info is written on all drives real-time or it is written on one drive and after that mirrored on another, what amount of drives are used for the RAID, and many others.
RAID in Shared Hosting
The SSD drives that our cutting-edge cloud hosting platform uses for storage function in RAID-Z. This sort of RAID is intended to work with the ZFS file system which runs on the platform and it uses the so-called parity disk - a special drive where information stored on the other drives is duplicated with an additional bit added to it. If one of the disks fails, your sites shall continue working from the other ones and as soon as we replace the bad one, the information that will be duplicated on it will be recovered from what is stored on the other drives together with the information from the parity disk. This is performed so as to be able to recalculate the bits of each file correctly and to authenticate the integrity of the data duplicated on the new drive. This is an additional level of security for the content that you upload to your shared hosting account along with the ZFS file system that compares a special digital fingerprint for every single file on all hard drives in real time.
RAID in Semi-dedicated Servers
The RAID type which we use for the cloud hosting platform where your semi-dedicated server account will be created is known as RAID-Z. What is different about it is that at least one of the disks is used as a parity drive. Put simply, whenever any data is cloned on this special disk drive, one more bit is added to it and in the event that a malfunctioning disk is changed, the info which will be duplicated on it is a combination of the data on the remaining drives in the RAID and that on the parity one. We do this to guarantee that your information is intact. Throughout this process, your websites will be working normally since RAID-Z allows 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 that uses checksums to warrant that no data will get silently corrupted on our servers, you won't need to worry about the integrity of your files.
RAID in VPS Servers
If you take advantage of one of our VPS server plans, any content you upload will be kept on SSD drives that operate in RAID. At least one drive is employed for parity so as to ensure the integrity of the information. In simple terms, this is a special drive where data is copied with one bit added to it. If a disk inside the RAID stops functioning, your websites will continue working and when a new disk replaces the malfunctioning one, the bits of the information that will be cloned on it are calculated using the healthy and the parity drives. That way, any chance of corrupting data throughout the process is avoided. We also employ ordinary hard drives which operate in RAID for storing backups, so should you include this service to your VPS package, your website content will be saved on multiple drives and you won't ever need to worry about its integrity even in the event of multiple drive failures.