RAID, or Redundant Array of Independent Disks, is a technology for keeping data on a number hard disk drives that function together as one logical unit. The drives could be physical or logical i.e. in the latter case a single drive is split into different ones using virtualization software. In either case, the very same info is saved on all of the drives and the key advantage of using this kind of a setup is that in case a drive breaks down, the data shall still be available on the remaining ones. Employing a RAID also improves the performance because the input and output operations will be spread among a number of drives. There are several types of RAID dependant upon how many hard drives are used, whether writing is done on all the drives in real time or just on one, and how the info is synced between the hard drives - whether it's written in blocks on one drive after another or it is mirrored from one on the others. All of these factors indicate that the fault tolerance and the performance between the various RAID types may differ.
RAID in Shared Hosting
The hard disks which we use for storage with our top-notch cloud Internet hosting platform are not the classic HDDs, but super fast solid-state drives (SSD). They operate in RAID-Z - a special setup intended for the ZFS file system that we work with. All of the content that you upload to your shared hosting account will be held on multiple drives and at least one of them will be used as a parity disk. This is a specific drive where a further bit is added to any content copied on it. In case a disk in the RAID stops working, it will be replaced without service disturbances and the data will be recovered on the new drive by recalculating its bits thanks to the data on the parity disk along with that on the other disks. This is done so as to ensure the integrity of the data and along with the real-time checksum authentication which the ZFS file system executes on all drives, you'll never need to be concerned about the loss of any info no matter what.
RAID in Semi-dedicated Servers
The info uploaded to any semi-dedicated server account is kept on SSD drives which operate in RAID-Z. One of the drives in this kind of a setup is used for parity - each time data is copied on it, an extra bit is added. If a disk turns out to be defective, it will be removed from the RAID without interrupting the work of the sites because the data will load from the other drives, and when a brand new drive is added, the information which will be cloned on it will be a blend between the information on the parity disk and data stored on the other hard drives in the RAID. That is done so as to ensure that the info that is being duplicated is accurate, so the moment the new drive is rebuilt, it could be included in the RAID as a production one. This is one more warranty for the integrity of your info since the ZFS file system which runs on our cloud Internet hosting platform compares a unique checksum of all the copies of your files on the different drives to avoid any chance of silent data corruption.
RAID in VPS Servers
If you use one of our VPS server plans, any content that you upload will be kept on SSD drives which work in RAID. At least a single drive is employed for parity so as to ensure the integrity of the info. In simple terms, this is a special drive where data is copied with one bit added to it. If a disk from the RAID stops functioning, your Internet sites will continue working and when a new disk replaces the defective one, the bits of the info that will be copied on it are calculated by using the healthy and the parity drives. By doing this, any chance of corrupting data during the process is averted. We also employ ordinary hard drives which work in RAID for storing backup copies, so if you include this service to your VPS package, your site content will be stored on multiple drives and you'll never need to worry about its integrity even in the event of multiple drive breakdowns.