RAID, or Redundant Array of Independent Disks, is a technology of saving data on a number hard disks which function together as a single logical unit. The drives could be physical or logical i.e. in the aforementioned case a single drive is divided into separate ones through virtualization software. Either way, identical data is kept on all drives and the basic advantage of employing this type of a setup is that in the event that a drive stops working, the data shall still be available on the other ones. Employing a RAID also improves the overall performance as the input and output operations will be spread among a number of drives. There are several kinds of RAID dependant upon how many hard disks are used, whether writing is performed on all drives in real time or just on one, and how the information is synchronized between the drives - whether it is recorded in blocks on one drive after another or all of it is mirrored from one on the others. These factors indicate that the fault tolerance and the performance between the different RAID types can differ.
RAID in Cloud Hosting
The drives that we use for storage with our outstanding cloud Internet hosting platform are not the classic HDDs, but quick solid-state drives (SSD). They operate in RAID-Z - a special setup intended for the ZFS file system that we employ. All of the content that you upload to the cloud hosting account will be saved on multiple hard drives and at least 1 will be used as a parity disk. This is a specific drive where an additional bit is included to any content copied on it. In case a disk in the RAID stops working, it will be replaced without any service disruptions and the info 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 so as to guarantee the integrity of the info and together with the real-time checksum validation which the ZFS file system performs on all drives, you will never need to worry about the loss of any data no matter what.
RAID in Semi-dedicated Servers
The RAID type that we employ for the cloud Internet hosting platform where your semi-dedicated server account shall be created is referred to as RAID-Z. What is different about it is that at least one of the disks is employed as a parity drive. In simple terms, whenever any kind of data is duplicated on this particular drive, one more bit is added to it and in case a problematic disk is changed, the data which will be copied on it is a mix of the data on the remaining disk drives in the RAID and that on the parity one. This is done to ensure that your info is intact. During this process, your Internet sites will be working normally since RAID-Z enables an entire drive to fail without service interruptions and it simply works by using one of the other ones as the main production drive. Employing RAID-Z together with the ZFS file system that uses checksums to warrant that no data will get silently corrupted on our servers, you won't need to worry about the integrity of your files.
RAID in VPS Servers
The SSD drives which we use on the machines where we generate VPS servers operate in RAID to make sure that any content which you upload will be available and intact at all times. At least a single drive is employed for parity - one bit of info is added to any data cloned on it. If a main drive breaks down, it is changed and the data that will be cloned on it is calculated between the rest of the drives and the parity one. That’s done to ensure that the required info is copied and that not a single file is corrupted as the new drive will be a part of the RAID afterwards. We also use hard disks operating in RAID on the backup servers, so in the event that you add this upgrade to your VPS plan, you shall use an even more reliable Internet hosting service because your content will be available on multiple drives irrespective of any unpredicted hardware failure.