Network Attached Secure Disks

Network-Attached Secure Disks (NASD) is 1997–2001 research project of Carnegie Mellon University, with the goal of providing cost-effective scalable storage bandwidth.

NASD reduces the overhead on the file server (file manager) by allowing storage devices to transfer data directly to clients. Most of the file manager's work is offloaded to the storage disk without integrating the file system policy into the disk. Most client operations like Read/Write go directly to the disks; less frequent operations like authentication go to the file manager. Disks transfer variable-length objects instead of fixed-size blocks to clients. The File Manager provides a time-limited cachable capability for clients to access the storage objects. A file access from the client to the disks has the following sequence:

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