RAID, which stands short for Redundant Array of Independent Disks, is a software or hardware storage virtualization technology that makes it possible for a system to employ multiple hard drives as a single logical unit. To put it differently, all drives are used as one and the information on all of them is identical. This type of a configuration has two huge advantages over using a single drive to save data - the first one is redundancy, so if one drive doesn't work, the data will be accessed through the others, and the second is better performance since the input/output, or reading/writing operations will be spread among several drives. You can find different RAID types in accordance with what number of drives are employed, if reading and writing are both performed from all of the drives concurrently, if data is written in blocks on one drive after another or is mirrored between drives in the same time, and many others. Determined by the particular setup, the error tolerance and the performance could differ.
RAID in Shared Hosting
The disk drives that we use for storage with our top-notch cloud web hosting platform are not the standard HDDs, but quick solid-state drives (SSD). They function in RAID-Z - a special setup created for the ZFS file system that we employ. Any content that you add to your shared hosting account will be saved on multiple disk drives and at least 1 shall be employed as a parity disk. This is a special drive where a further bit is added to any content copied on it. If a disk in the RAID stops working, it'll be replaced without service interruptions and the info will be rebuilt on the new drive by recalculating its bits using the data on the parity disk along with that on the other disks. This is done to guarantee the integrity of the data and together with the real-time checksum verification that the ZFS file system performs on all drives, you won't ever need to worry about the loss of any info no matter what.
RAID in Semi-dedicated Hosting
The info uploaded to any semi-dedicated hosting account is saved on SSD drives that function in RAID-Z. One of the drives in this kind of a configuration is used for parity - each time data is copied on it, an additional bit is added. In case a disk turns out to be defective, it will be taken out of the RAID without disturbing the work of the Internet sites since the data will load from the rest of the drives, and when a brand new drive is added, the data that will be duplicated on it will be a blend between the data on the parity disk and data saved on the other drives in the RAID. That is done to ensure that the information which is being cloned is correct, so once the new drive is rebuilt, it could be integrated into the RAID as a production one. This is an extra guarantee for the integrity of your information since the ZFS file system which runs on our cloud web hosting platform analyzes a unique checksum of all the copies of the files on the various drives to avoid any possibility of silent data corruption.
RAID in VPS Hosting
The SSD drives which we use on the machines where we create virtual private servers operate in RAID to ensure that any content that you upload will be available and intact all the time. At least 1 drive is used for parity - one bit of information is added to any data cloned on it. If a main drive breaks down, it is changed and the information that will be cloned on it is calculated between the other drives and the parity one. That’s done to ensure that the required info is copied and that not a single file is corrupted since the new drive will be incorporated into the RAID afterwards. We also use hard disk drives functioning in RAID on the backup servers, so in case you add this upgrade to your VPS package, you shall use an even more reliable web hosting service since your content will be available on multiple drives regardless of any sudden hardware malfunction.