Disk as a file system (NAS) remains survey respondents' most popular type of disk backup target. Almost half of respondents reported already using NAS for D2D backup in 2012, and almost 40% said they planned to add the technology, a five-percentage-point increase in four years. Nearly a third of survey respondents planned to add backup dedupe technology, building on the technology's installed base of 36%. Virtual tape libraries (VTL), meanwhile, have dropped in importance significantly. Only 16% of respondents reported current use of VTL for backup, and only 11% planned to add VTL for backup in 2012 (compared with 24% in 2008).