When it comes to deploying RAID, there are two types of RAID:
- Hardware RAID (see Figure 9.11) is an expensive solution and requires configuration prior to installing the OS. It is an electronic board that either the manufacturer of the server or you will plug into an adequate slot on the server's motherboard:

Figure 9.11: The RAID controller
- Software RAID is a cheaper solution and is configured after the installation of an OS. It is an application that you will end up buying from a specific vendor.
Now, let's understand SDS.