RAID, or Redundant Array of Independent Disks, is a technology of saving data on several hard disks which work together as one logical unit. The drives can be physical or logical i.e. in the second case a single drive is split into individual ones through virtualization software. Either way, the very same data is stored on all drives and the key advantage of using such a setup is that in case a drive breaks down, the data shall still be available on the remaining ones. Having a RAID also improves the performance as the input and output operations will be spread among a few drives. There are several types of RAID dependant upon how many hard disks 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 hard 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 mean that the error tolerance and the performance between the different RAID types can differ.
RAID in Shared Hosting
All of the content which you upload to your new shared hosting account will be placed on fast SSD drives that operate in RAID-Z. This configuration is built to work with the ZFS file system that runs on our cloud Internet hosting platform and it adds another level of security for your site content on top of the real-time checksum verification which ZFS uses to ensure the integrity of the data. With RAID-Z, the information is stored on several disks and at least 1 is a parity disk - whenever information is written on it, an extra bit is added, so in case any drive stops working for some reason, the stability of the data can be verified by recalculating its bits in accordance with what is stored on the production drives and on the parity one. With RAID-Z, the operation of our system will not be interrupted and it'll continue working efficiently until the problematic drive is changed and the information is synced on it.
RAID in Semi-dedicated Servers
The SSD drives which are used for keeping any site content uploaded to the semi-dedicated server accounts that we offer function in RAID-Z. This is a special configuration where one or more disk drives are used for parity i.e. the system will include an additional bit to any data copied on such a drive. In case that a disk fails and is replaced with a new one, what information will be copied on the latter will be a combination calculated between the data on the remaining disks and that on the parity one. This is done to ensure that the info on the new drive will be accurate. Throughout the procedure, the RAID will continue working adequately and the problematic drive won't impact the normal operation of your Internet sites in any way. Using SSDs in RAID-Z is an outstanding addition to the ZFS file system that runs on our cutting-edge cloud platform with regards to preserving the integrity of your files since ZFS uses unique digital identifiers known as checksums in order to prevent silent data corruption.