An algorithm of node collection in Distributed File System based on mathematical expectation

For conquering the effect of data transmission in user access to the randomness between system and user in distributed virtual environment, in this paper algorithm of node collection in DFS (Distributed File System) based on expectation is presented. We present the mathematical model and calculation steps too. And in this paper we propose not only the application of a polynomial function fitting the user with the speed sets on the network node cluster but also the tactics of calculation the max expectation from the function Fitting. Simulations show that we can find the best node in every area and different sessions from this algorithm and tactic.