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What is NAStore?
NAStore is a free, Network Attachable Storage system, providing a file system that migrates file data to removable storage (such as tape), bringing it back when a user accesses a file (also known as a Hierarchical Storage Management System, or HSM). This allows storage capacity to be expanded beyond the amount of affordable disk, and provides automatic backup of files on an ongoing basis.
Components Are Individually Useful
NAStore consists of several main components, some of which can also be used as components in other storage systems or user applications. The file system part requires operating system kernel support; but the other components are of a general UNIX nature. These include the Volume Manager (volman), which manages removable media such as tapes and CDs, including their robotic autochangers, and the Virtual Volume Manager (vvm), which migrates chunks of data known as virtual volumes between removable media and a disk cache, which can be shared by multiple hosts.
Can Be Run in a Distributed Environment
The parts of NAStore can all be run on the filesystem host, or volman and vvm can be distributed to other hosts. Data can be saved in multiple copies to different types of media and (in distributed mode) to different locations. Tape or CD drives might also be distributed to dedicated servers to enhance storage bandwidth.
The NAStore file system has so far been implemented for NetBSD (not released yet). The other components should run on any UNIX-based system, and have also been run on IRIX and SunOS.
NAStore was developed at the Numerical Aerodynamic Simulation supercomputer center (NAS) at the NASA Ames Research Center in Silicon Valley. It was open-sourced in 2000, and this site set up privately by the developers to distribute it for free.