Proper disk configuration ensures that your SQL Server implementations are highly available and deliver the performance that you need from your disk subsystem. Planning can prevent future problems due to growth, performance, or disk availability. It is sometimes better to buy enough disk storage spacethat is, the physical enclosure spaceup front than it is to buy all of your disks at once. If your disk solution supports dynamic or easier growth, you can maximize your hardware investment, as you have planned for all of your growth but can expand when you need it. Using multiple controllers to support different types of reads and writes might be optimal, but it is expensive. Whatever you buy and implement affects every other aspect of your SQL Server and application solution.