(Disk-to-Disk) Typically refers to backing up data on disks rather than on tape. Disk-to-disk backup systems provide a very fast restore capability compared with tape backup. See D2D2T, virtual tape and X2X.
"D2D." YourDictionary, n.d. Web. 17 August 2018. <http://www.yourdictionary.com/d2d>.
D2D. (n.d.). Retrieved August 17th, 2018, from http://www.yourdictionary.com/d2d