As digital data storage becomes increasingly vast and sensitive—particularly for businesses—new challenges develop to ensure data availability reliably and securely. Storage subsystems must be enhanced to protect against errors developing in increasingly large storage systems while sustaining the enormous throughput and low-latency offered by solid-state storage. Future storage systems must scale to enable big data analytics applications while still being cost-efficient by storing data according to its value. Flexible and easy-to-use multi-tiered storage systems incorporating technologies such as flash, hard disk drives, and magnetic tapes are required. Furthermore, caching technologies and flash memory management in virtualized and distributed storage environments need to be advanced and new storage-class memory technologies such as phase change memory (PCM) must be integrated into the existing storage stack. Finally, the security properties of such storage systems must be clearly understood and designed, particularly in the case of multi-tenant cloud environments.