Redundant Array of Independent Disks, or RAID, is a method of saving content on a number of hard disk drives simultaneously. A RAID might be software or hardware depending on the drives which are used - physical or logical ones, yet what is common between them is that they all perform as just a single unit where info is kept. The key advantage of using a RAID is redundancy as the information on all drives will be the same at all times, so even in case one of the drives fails for whatever reason, the info will still be available on the other drives. The overall performance is also enhanced because the reading and writing processes will be split between a number of drives, so a single one won't be overloaded. There are different sorts of RAIDs where the performance and fault tolerance may differ according to the particular setup - whether information is written on all the drives in real time or it is written on a single drive and after that mirrored on another, what amount of drives are used for the RAID, and so on.
RAID in Shared Website Hosting
The advanced cloud hosting platform where all shared website hosting
accounts are created uses super fast SSD drives rather than the standard HDDs, and they function in RAID-Z. With this setup, several hard drives function together and at least 1 is a dedicated parity disk. Basically, when data is written on the other drives, it's duplicated on the parity one adding an extra bit. This is done for redundancy as even in case a drive fails or falls out of the RAID for whatever reason, the information can be rebuilt and verified thanks to the parity disk and the data saved on the other ones, so practically nothing will be lost and there will be no service disturbances. This is an additional level of protection for your information in addition to the top-notch 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 RAID type which we employ for the cloud hosting platform where your semi-dedicated server
account will be created is named RAID-Z. What is different about it is that at least 1 of the disks is used as a parity drive. Put simply, whenever any data is copied on this specific drive, one more bit is added to it and if a faulty disk is replaced, the data which will be duplicated on it is a combination of the data on the other disk drives in the RAID and that on the parity one. It's done this way to guarantee that your data is intact. Throughout this process, your Internet sites will be working normally as RAID-Z makes it possible for a whole drive to fail without service disturbances and it simply works by using one of the remaining ones as the main production drive. Employing RAID-Z together with the ZFS file system which uses checksums to ensure that no data will get silently corrupted on our servers, you'll never need to worry about the integrity of your files.