Redundant Array of Independent Disks, or RAID, is a way of keeping content on multiple hard disk drives simultaneously. A RAID might be software or hardware depending on the HDDs which are used - physical or logical ones, still what is common between them is the fact that they all operate as just one single unit where data is stored. The main advantage of using a RAID is redundancy because the info on all drives will be identical at all times, so even in case a drive fails for whatever reason, the information will still be present on the other drives. The general performance will also improve since the reading and writing processes could be split between various drives, so a single one can't be overloaded. There're different types of RAIDs where the capabilities and fault tolerance may vary depending on the specific setup - whether your data is written on all drives in real time or it is written on a single drive and then mirrored on another, what amount of drives are used for the RAID, and many others.
RAID in Shared Hosting
The NVMe drives which our cutting-edge cloud Internet hosting platform uses for storage operate in RAID-Z. This sort of RAID is designed to work with the ZFS file system which runs on the platform and it employs the so-called parity disk - a special drive where information located on the other drives is cloned with an extra bit added to it. In the event that one of the disks stops functioning, your sites will continue working from the other ones and after we replace the problematic one, the data that will be copied on it will be recovered from what is stored on the remaining drives as well as the data from the parity disk. This is performed so as to be able to recalculate the bits of each and every file adequately and to confirm the integrity of the information duplicated on the new drive. This is another level of security for the content that you upload to your shared hosting account in addition to the ZFS file system which compares a unique digital fingerprint for each file on all of the disk drives in real time.
RAID in Semi-dedicated Servers
The RAID type which we employ for the cloud hosting platform where your semi-dedicated server account will be created is called RAID-Z. What's 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 particular drive, one more bit is added to it and if a malfunctioning disk is changed, the information that will be duplicated on it is a combination of the data on the other hard disks in the RAID and that on the parity one. We do this to make sure that the data is intact. During this process, your websites will be functioning normally as RAID-Z enables an entire drive to fail without causing any service disturbances and it simply uses one of the remaining ones as the main production drive. Using RAID-Z together with the ZFS file system which uses checksums to guarantee that no data will get silently corrupted on our servers, you won't need to worry about the integrity of your files.