NAS file-level storage ranges from standalone desktop boxes to huge clusters that scale for capacity and performance and deliver billions of files from parallel file systems. In this guide to NAS management, we examine what the future holds for NAS, and we look at NAS products from vendors in a number of categories: scale-out NAS, traditional NAS, desktop NAS. We consider how scale-out NAS is meeting the unstructured data challenge, how traditional NAS is still meeting the needs of SMBs, how clustered NAS compares with traditional NAS, and the key characteristics of desktop NAS.