Redundant Array of Independent Disks, or RAID, is a method of keeping content on several hard disk drives at the same time. A RAID can be software or hardware depending on the drives that are used - physical or logical ones, still what’s common between them is the fact that they all operate as a single unit where data is kept. The main advantage of using a RAID is redundancy because the information on all drives will be exactly the same at all times, so even in the event that one of the drives fails for some reason, the info will still be available on the rest of the drives. The overall performance is enhanced as well as the reading and writing processes can be split between different drives, so a single one won't be overloaded. There're different sorts of RAIDs where the efficiency and fault tolerance may differ depending on the exact setup - whether your data is written on all the drives in real time or it is written on a single drive and after that mirrored on another, the number of drives are used for the RAID, and many others.
RAID in Shared Hosting
Our state-of-the-art cloud hosting platform where all shared hosting accounts are made uses quick SSD drives as an alternative to the traditional HDDs, and they operate in RAID-Z. With this setup, several hard drives function together and at least 1 is a dedicated parity disk. Put simply, when data is written on the other drives, it's duplicated 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 info can be rebuilt and verified thanks to the parity disk and the data stored on the other ones, therefore not a single thing will be lost and there won't be any service disturbances. This is another level of protection for your info along with the advanced ZFS file system which uses checksums to make sure that all of the data on our servers is undamaged and is not silently corrupted.
RAID in Semi-dedicated Servers
In case you host your websites in a semi-dedicated server account from our company, all the content that you upload will be kept on SSD drives which work in RAID-Z. With this kind of RAID, at least one of the hard disks is employed for parity - when data is synchronized between the hard drives, an additional bit is included in it on the parity one. The purpose behind this is to guarantee the integrity of the data which is copied to a new drive if one of the drives in the RAID breaks down as the site 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 hard drive stops working, the system can easily switch to a different one right away without service disruptions of any sort. RAID-Z adds an extra level of protection for the content that you upload on our cloud web hosting platform along with the ZFS file system that uses unique checksums as a way to validate the integrity of each file.
RAID in VPS Servers
The SSD drives which we use on the machines where we generate VPS servers work in RAID to make sure that any content you upload will be available and intact all of the time. At least a single drive is used for parity - one bit of info is added to any data copied on it. In case a main drive stops working, it is changed and the info which will be copied on it is calculated between the remaining drives and the parity one. This is done to ensure that the needed information is copied and that not a single file is corrupted because the new drive will be used in the RAID afterwards. We also use hard drives working in RAID on the backup servers, so in the event that you add this upgrade to your VPS package, you'll use an even more reliable hosting service because your content will be available on multiple drives irrespective of any kind of unexpected hardware malfunction.