Redundant Array of Independent Disks, or RAID, is a way of saving content on a number of hard disks simultaneously. A RAID might be software or hardware depending on the drives which are used - physical or logical ones, but what’s common between them is the fact that they all work as one single unit where data is stored. The main advantage of using a RAID is redundancy as the info on all the drives will be identical at all times, so even in the event that some drive fails for some reason, the information will still be present on the rest of the drives. The general performance will also improve because the reading and writing processes can be split between a number of drives, so a single one can't be overloaded. There are different types of RAIDs where the effectiveness and fault tolerance may vary depending on the exact setup - whether info is written on all the 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 Website Hosting
The drives that we employ for storage with our revolutionary cloud hosting platform are not the classic HDDs, but quick solid-state drives (SSD). They function in RAID-Z - a special setup designed for the ZFS file system which we use. Any content that you upload to your website hosting
account will be saved on multiple hard drives and at least 1 shall be used as a parity disk. This is a special drive where an additional bit is added to any content copied on it. In the event that a disk in the RAID stops working, it will be changed with no service disturbances and the info will be rebuilt on the new drive by recalculating its bits thanks to the data on the parity disk plus that on the other disks. This is done in order to guarantee the integrity of the info and together with the real-time checksum verification that the ZFS file system performs on all drives, you will never need to be concerned about the loss of any information no matter what.
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 referred to as RAID-Z. What's different about it is that at least one of the disks is used as a parity drive. In simple terms, whenever any data is cloned on this special hard drive, one more bit is added to it and if a defective disk is replaced, the information which will be duplicated on it is a mix of the data on the other drives in the RAID and that on the parity one. We do this to ensure that the information is intact. During this process, your websites will be functioning normally as RAID-Z enables a whole drive to fail without any service disturbances and it simply uses one of the other 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'll never need to worry about the integrity of your files.