Cache Management Algorithms for Flexible Filesystems

Cache management in flexible filesystems deals with the problem of determining a cached file to be replaced when the local cachespace is exhausted. In analogy to virtual memory management, several different algorithms exist for managing cached files. In this paper we simulate the behavior of First-In-First-Out (FIFO), Least Recently Used (LRU), Least Frequently Used (LFU) and a variation of LFU we call the File Length Algorithm (LEN) from the viewpoint of file access times, cache hit ratios and availability. The results of several simulation runs are presented and interpreted. Keywords: Cache Management, File Access, Flexible Filesystems, Replication 1 Introduction For virtual storage management, Denning [4] developed a view of program paging activity called the workingset model. The workingset model is based on the assumption of locality of reference. The idea is to examine the most recent \Delta page-references of a process P. The set of pages accessed by the most recent \Delta pag..