RAID, or Redundant Array of Independent Disks, is a technology for saving data on a number hard drives that work together as one single logical unit. The drives could be physical or logical i.e. in the latter case one drive is divided into independent ones using virtualization software. In any case, the very same data is stored on all drives and the main benefit of employing such a setup is that if a drive fails, the data will still be available on the other ones. Using a RAID also improves the performance because the input and output operations will be spread among a number of drives. There are several kinds of RAID dependant upon how many hard drives are used, whether writing is performed on all the drives in real time or just on one, and how the information is synchronized between the drives - whether it's written in blocks on one drive after another or all of it is mirrored from one on the others. All these factors show that the error tolerance as well as the performance between the different RAID types can vary.

RAID in Cloud Web Hosting

All content that you upload to your new cloud web hosting account will be stored on fast SSD drives which function in RAID-Z. This configuration is built to use the ZFS file system which runs on our cloud hosting platform and it adds an additional level of security for your site content in addition to the real-time checksum validation which ZFS uses to guarantee the integrity of the data. With RAID-Z, the information is stored on several disks and at least one of them is a parity disk - whenever info is written on it, an additional bit is added, so in case any drive stops working for some reason, the integrity of the info can be verified by recalculating its bits based on what is stored on the production hard disks and on the parity one. With RAID-Z, the functioning of our system won't be interrupted and it will continue working flawlessly until the problematic drive is replaced and the info is synced on it.

RAID in Semi-dedicated Servers

The info uploaded to any semi-dedicated server account is saved on SSD drives that function in RAID-Z. One of the drives in type of a configuration is used for parity - any time data is cloned on it, an additional bit is added. If a disk turns out to be problematic, it will be taken out of the RAID without disturbing the work of the sites since the data will load from the other drives, and when a new drive is included, the information which will be copied on it will be a combination between the info on the parity disk and data stored on the other drives in the RAID. This is done to ensure that the information which is being copied is accurate, so once the new drive is rebuilt, it can be included in the RAID as a production one. This is an extra guarantee for the integrity of your data since the ZFS file system which runs on our cloud hosting platform compares a special checksum of all of the copies of your files on the different drives to be able to avoid any probability of silent data corruption.

RAID in VPS Servers

The SSD drives which we use on the physical machines where we set up VPS servers work 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 used for parity - one bit of data is added to any data cloned on it. In case a main drive breaks down, it is changed and the info that will be cloned on it is calculated between the remaining drives and the parity one. This is done to ensure that the required information is copied and that no file is corrupted as the new drive will be used in the RAID afterwards. Also, we use hard disks working in RAID on the backup servers, so if you add this upgrade to your VPS plan, you'll use an even more reliable web hosting service because your content will be available on multiple drives irrespective of any kind of unpredicted hardware failure.