RAID, or Redundant Array of Independent Disks, is a technology of keeping data on multiple hard disk drives which function together as one logical unit. The drives could be physical or logical i.e. in the aforementioned case one drive is split into individual ones using virtualization software. In any case, the same data is kept on all the drives and the key advantage of using such a setup is that if a drive breaks down, the data shall still be available on the remaining ones. Having a RAID also boosts the overall performance because the input and output operations will be spread among a few drives. There are several types of RAID based on how many hard drives are used, whether writing is carried out on all of the drives in real time or just on a single one, and how the info is synced between the hard drives - whether it is written in blocks on one drive after another or all of it is mirrored from one on the others. All of these factors imply that the fault tolerance as well as the performance between the different RAID types may differ.

RAID in Shared Hosting

The advanced cloud web hosting platform where all shared hosting accounts are created employs quick SSD drives as an alternative to the traditional HDDs, and they operate in RAID-Z. With this configuration, a number of hard drives operate together and at least 1 is a dedicated parity disk. Put simply, when data is written on the other drives, it's cloned on the parity one adding an extra bit. This is carried out for redundancy as even if a drive fails or falls out of the RAID for whatever reason, the info can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, thus absolutely nothing will be lost and there will be no service disturbances. This is one more level of protection for your information together with the state-of-the-art ZFS file system that uses checksums to guarantee that all data on our servers is intact and is not silently corrupted.

RAID in Semi-dedicated Hosting

The info uploaded to any semi-dedicated hosting account is kept on SSD drives that work in RAID-Z. One of the drives in such 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 faulty, it will be taken out of the RAID without interrupting the functioning of the Internet sites since the data will load from the rest of the drives, and when a new drive is added, the data which will be copied on it will be a mix between the data on the parity disk and data saved on the other hard drives in the RAID. This is done so as to guarantee that the data that is being duplicated is accurate, so once the new drive is rebuilt, it can be integrated into the RAID as a production one. This is an extra guarantee for the integrity of your data since the ZFS file system that runs on our cloud web hosting platform compares a special checksum of all the copies of your files on the separate drives to be able to avoid any chance of silent data corruption.