RAID, or Redundant Array of Independent Disks, is a technology for keeping data on multiple hard drives that work together as one single logical unit. The drives can be physical or logical i.e. in the second case a single drive is divided into separate ones through virtualization software. Either way, the very same information is stored on all drives and the key benefit of employing such a setup is that if a drive breaks down, the data will remain available on the other ones. Employing a RAID also enhances the performance since the input and output operations will be spread among a few drives. There are several types of RAID depending on 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 synced between the hard drives - whether it's recorded in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors mean that the error tolerance as well as the performance between the various RAID types may differ.
RAID in Shared Hosting
The cutting-edge cloud hosting platform where all shared hosting accounts are made employs quick NVMe drives as an alternative to the standard HDDs, and they work in RAID-Z. With this setup, a number of hard disks function together and at least one of them is a dedicated parity disk. Basically, when data is written on the other drives, it's cloned on the parity one adding an extra bit. This is done for redundancy as even if a drive fails or falls out of the RAID for some reason, the information can be rebuilt and verified using the parity disk and the data recorded on the other ones, thus not a single thing will be lost and there will not be any service disorders. This is another level of protection for your information together with the state-of-the-art ZFS file system that uses checksums to ensure that all of the data on our servers is intact and is not silently corrupted.
RAID in Semi-dedicated Hosting
If you host your sites within a semi-dedicated hosting account from our firm, all the content which you upload will be saved on NVMe drives which work in RAID-Z. With this form of RAID, at least 1 of the disks is employed for parity - when data is synced between the disks, an extra bit is included in it on the parity one. The reasoning behind this is to ensure the integrity of the data which is cloned to a brand new drive in case one of the hard drives in the RAID stops working because the content being copied on the new disk is recalculated from the data on the standard drives and on the parity one. An additional advantage of RAID-Z is that even in case a drive stops working, the system can easily switch to a different one promptly without service interruptions of any sort. RAID-Z adds an extra level of safety for the content that you upload on our cloud Internet hosting platform along with the ZFS file system that uses unique checksums as a way to authenticate the integrity of each file.
The NVMe drives which we use on the physical machines where we set up virtual private servers operate in RAID to ensure that any content which you upload will be available and intact at all times. At least 1 drive is used for parity - one bit of information is added to any data copied on it. In case a main drive fails, it is replaced 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 right information is copied and that no file is corrupted as the new drive will be incorporated into the RAID afterwards. In addition, we use hard disks working in RAID on the backup servers, so in case you add this upgrade to your VPS package, you'll use an even more reliable hosting service as your content will be available on multiple drives irrespective of any kind of unexpected hardware failure.