A cluster table contains information about each cluster on disk: the status, last-time accessed, and a linked list of the files in the cluster. The cluster status field identifies whether the cluster is empty, on disk, or in memory. For our file system, the cluster ID identifies the location of the cluster on disk. While a cluster is in memory, the address of the cluster in memory is needed. The last-time accessed is needed to determine the amount of time since the cluster was last touched.