RAID, or Redundant Array of Independent Disks, is a technology for keeping data on several hard disks which function together as one single logical unit. The drives could be physical or logical i.e. in the aforementioned case a single drive is split into different ones through virtualization software. In any case, identical information is saved on all drives and the key benefit of using this kind of a setup is that if a drive fails, the data will still be available on the remaining ones. Using a RAID also enhances the overall performance since the input and output operations will be spread among a couple of drives. There are several types of RAID based on how many drives are used, whether writing is carried out on all of the drives in real time or just on one, and how the info is synchronized between the drives - whether it is written in blocks on one drive after another or it is mirrored from one on the others. These factors indicate that the fault tolerance as well as the performance between the various RAID types can differ.
RAID in Shared Web Hosting
The disk drives that we employ for storage with our ground-breaking cloud web hosting platform are not the standard HDDs, but extremely fast solid-state drives (SSD). They operate in RAID-Z - a special setup created for the ZFS file system which we use. Any content that you add to your shared web hosting account will be saved on multiple disk drives and at least one of them will 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 will be replaced without any service interruptions and the information will be recovered on the new drive by recalculating its bits using the data on the parity disk plus that on the remaining disks. This is done in order to ensure the integrity of the information and together with the real-time checksum validation that the ZFS file system performs on all drives, you'll never need to worry about losing any information no matter what.
RAID in Semi-dedicated Hosting
The RAID type which we employ for the cloud Internet hosting platform where your semi-dedicated hosting account shall be created is named RAID-Z. What's different about it is that at least 1 of the disks is used as a parity drive. Simply put, whenever any kind of data is cloned on this particular disk drive, one more bit is included to it and in case a faulty disk is replaced, the data that will be duplicated on it is a combination of the data on the other hard drives in the RAID and that on the parity one. This is done to guarantee that your data is intact. During this process, your Internet sites will be functioning normally as RAID-Z enables a whole drive to fail without service disturbances and it simply uses one of the other ones as the main production drive. Employing RAID-Z together with the ZFS file system which uses checksums to warrant that no data shall get silently corrupted on our servers, you'll never need to worry about the integrity of your files.
RAID in VPS Hosting
The SSD drives that we use on the physical machines where we generate virtual private servers function in RAID to make sure that any content you upload will be available and intact all the time. At least a single drive is employed for parity - one bit of data is added to any data copied on it. In case a main drive breaks down, it is replaced and the data which will be cloned on it is calculated between the other drives and the parity one. It's done this way to make sure that the right data is copied and that not a single file is corrupted since the new drive will be a part of the RAID afterwards. Also, we use hard drives operating in RAID on the backup servers, so in case you add this upgrade to your VPS plan, you'll use an even more reliable Internet hosting service because your content will be available on multiple drives irrespective of any sort of unforeseen hardware malfunction.