Redundant Array of Independent Disks, or RAID, is a way of keeping content on multiple hard drives simultaneously. A RAID can be software or hardware based on the drives that are used - physical or logical ones, still what is common between them is that they all operate as one single unit where your information is stored. The biggest advantage of employing a RAID is redundancy since the information on all of the drives will be identical all of the time, so even in the event that some drive fails for some reason, the information will still be available on the remaining drives. The general performance is also better because the reading and writing processes could be split between multiple drives, so a single one won't be overloaded. There're different types of RAIDs where the capabilities and fault tolerance can vary depending on the particular setup - whether data is written on all the drives real-time or it's written on one drive and afterwards mirrored on another, what number of drives are used for the RAID, etc.
RAID in Website Hosting
All content which you upload to your new website hosting account will be stored on quick SSD drives which function in RAID-Z. This configuration is built to work with the ZFS file system which runs on our cloud hosting platform and it adds an additional level of protection for your site content on top of the real-time checksum validation which ZFS uses to ensure the integrity of the data. With RAID-Z, the info is stored on several disks and at least one is a parity disk - whenever information is recorded on it, an extra bit is added, so in the event that any drive fails for some reason, the stability of the information can be verified by recalculating its bits based on what is saved on the production hard drives and on the parity one. With RAID-Z, the operation of our system won't be interrupted and it will continue working smoothly until the problematic drive is changed and the information is synchronized on it.
RAID in Semi-dedicated Servers
The data uploaded to any semi-dedicated server account is stored on SSD drives that function in RAID-Z. One of the drives in such a configuration is used for parity - any time data is cloned on it, an extra bit is added. If a disk happens to be problematic, it will be taken out of the RAID without interrupting the functioning of the websites because the data will load from the rest of the drives, and when a brand new drive is included, the info that will be cloned on it will be a blend between the data on the parity disk and data stored on the other hard disks in the RAID. This is done to ensure that the information which is being duplicated is correct, so once the new drive is rebuilt, it could be integrated into the RAID as a production one. This is one more warranty for the integrity of your data because the ZFS file system that runs on our cloud hosting platform compares a unique checksum of all copies of your files on the various drives to be able to avoid any chance of silent data corruption.