RAID, or Redundant Array of Independent Disks, is a technology of storing data on several hard disk drives that operate together as a single logical unit. The drives can be physical or logical i.e. in the aforementioned case a single drive is divided into independent ones using virtualization software. In any case, identical info is saved on all the drives and the basic advantage of using this kind of a setup is that in the event that a drive stops working, the data will remain available on the remaining ones. Having a RAID also boosts the performance because the input and output operations will be spread among a few drives. There are several types of RAID depending on how many drives are used, whether writing is carried out on all drives in real time or just on one, and how the data is synchronized between the drives - whether it's written in blocks on one drive after another or it is mirrored from one on the others. All of these factors mean that the error tolerance as well as the performance between the different RAID types could differ.
RAID in Cloud Website Hosting
All content that you upload to your new cloud website hosting
account will be stored on quick SSD drives that operate in RAID-Z. This setup is built to use the ZFS file system which runs on our cloud web hosting platform and it adds one more level of protection for your content in addition to the real-time checksum authentication which ZFS uses to ensure the integrity of the data. With RAID-Z, the information is saved on a number of disks and at least one is a parity disk - whenever info is written on it, an additional bit is added, so in case any drive stops functioning for whatever reason, the integrity of the info can be verified by recalculating its bits in accordance with what is stored on the production disks and on the parity one. With RAID-Z, the functioning of our system will not be interrupted and it will continue operating efficiently until the faulty drive is replaced and the info is synchronized on it.
RAID in Semi-dedicated Servers
The data uploaded to any semi-dedicated server
account is stored on SSD drives that function in RAID-Z. One of the drives in this kind of a configuration is used for parity - every time data is cloned on it, an extra bit is added. In case a disk happens to be flawed, it will be removed from the RAID without interrupting the functioning of the websites because the data will load from the remaining drives, and when a brand new drive is included, the information that will be copied on it will be a mix between the information on the parity disk and data saved on the other hard disks in the RAID. That is done so as to guarantee that the data that is being cloned is correct, so the moment the new drive is rebuilt, it can be integrated into the RAID as a production one. This is an additional guarantee for the integrity of your information because the ZFS file system which runs on our cloud web hosting platform analyzes a unique checksum of all the copies of your files on the different drives to be able to avoid any possibility of silent data corruption.