Modeling Background

The issues of file access pattern modeling have been explored previously [12,13,14,15]. We present a brief background on the three modeling techniques used in our implementation: last-successor, Partitioned Context Modeling and Extended Partitioned Context Modeling.

The last-successor model was used as a simple baseline for comparison. This model predicts that an access to file A will be followed by an access to the same file that followed the last access to A. This model requires only one node per unique file so we can say that its state space is O(n), where n is the number of unique files. We saw that for a wide variety of file system traces this last successor model was able to correctly predict the next access an average of 72% of the time [13].