RAID, which is an acronym of Redundant Array of Independent Disks, is a software or hardware storage virtualization technology which permits a system to take advantage of a number of hard drives as one single logical unit. In other words, all the drives are used as one and the data on all of them is the same. This kind of a configuration has two huge advantages over using a single drive to save data - the first is redundancy, so if one drive stops working, the information will be accessible through the remaining ones, and the second is improved performance since the input/output, or reading/writing operations will be spread among several drives. There're different RAID types in accordance with what amount of drives are employed, if reading and writing are both executed from all drives simultaneously, whether data is written in blocks on one drive after another or is mirrored between drives in the same time, etc. According to the exact setup, the fault tolerance and the performance vary.
RAID in Cloud Hosting
The drives which we employ for storage with our innovative cloud web hosting platform are not the traditional HDDs, but fast solid-state drives (SSD). They operate in RAID-Z - a special setup intended for the ZFS file system which we employ. Any content that you upload to your cloud hosting account will be saved on multiple hard drives and at least one will be employed as a parity disk. This is a specific drive where an additional bit is added to any content copied on it. In the event that a disk in the RAID fails, it will be replaced without service disruptions and the data will be recovered on the new drive by recalculating its bits thanks to the data on the parity disk plus that on the remaining disks. This is done in order to guarantee the integrity of the info and along with the real-time checksum authentication which the ZFS file system runs on all drives, you will never have to be concerned about losing any information no matter what.
RAID in Semi-dedicated Servers
The information uploaded to any semi-dedicated server account is saved on SSD drives that work in RAID-Z. One of the drives in this kind of a configuration is used for parity - every time data is copied on it, an extra bit is added. In case a disk turns out to be defective, it will be taken out of the RAID without interrupting the operation of the websites as the data will load from the rest of the drives, and when a new drive is included, the info which will be cloned on it will be a blend between the info on the parity disk and data stored on the other drives in the RAID. That is done to ensure that the info that is being duplicated is accurate, so once the new drive is rebuilt, it could be incorporated into the RAID as a production one. This is an extra warranty for the integrity of your information as the ZFS file system which runs on our cloud Internet hosting platform analyzes a special checksum of all the copies of your files on the separate drives to avoid any probability of silent data corruption.
RAID in VPS Servers
The SSD drives which we use on the physical machines where we create VPS servers work in RAID to make sure that any content that you upload will be available and intact all of the time. At least one drive is used for parity - one bit of information is added to any data cloned on it. In case a main drive breaks down, it is changed and the data which will be copied on it is calculated between the other drives and the parity one. That’s done to make sure that the required info is copied and that no file is corrupted as the new drive will be incorporated into the RAID afterwards. We also use hard disks functioning in RAID on the backup servers, so in case you add this upgrade to your VPS plan, you'll use an even more reliable web hosting service because your content will be available on multiple drives irrespective of any sort of unforeseen hardware failure.