Netcache: A Distributed Buffercache Extension

Netcache is a new distributed buffercache system that is designed to exploit the resources on a local area network to improve the performance of disk reads and other block I/O read accesses. The typical round-trip latency on an Ethernet segment is roughly an order of magnitude shorter than the seek time of a hard disk, and the size of the pool of unused RAM is potentially large; Netcache exploits this available storage as an extra layer of cache for block I/O operations. This paper discusses the theory, protocol, security implications, implementation details, performance analysis, and plans and ideas for future functionality enhancements of Netcache. Netcache has been implemented and tested as part of the Linux kernel's buffercache, and the results are very promising