The primary goal of a storage infrastructure is to store data. There are two issues that needed to be considered when dealing with data storage, as follows:

• Capacity: The capacity refers to how much storage one should allocate (or what size the memory should be) in order to store data.
• Scalability: The attached storage devices should be scalable, as the volume of data will grow over time. Also, scalability deals with the ability to connect to the network in order to get extra storage over time. 

In a big data system, we have the choice of architecting a storage infrastructure by choosing how much of each type of storage we need to have. Using SSDs for storing a large amount of data speeds up lookup operations in the data by at least a factor of ten over hard drives; however, it also increases the cost.