nonresident lru queue there may however be cl records allocated for use in case the amount of cache memory 32 is dynamically increased as discussed in more detail below any allocated cl records which are not in use are kept on a free list which is a singly linked list of cl records that are not currently in use as illustrated in fig3 the first cl record on the free list is identified by the free list pointer 49 the first cl record on the free list includes in its working set queue pointer 60 a pointer to the second cl record on the free list subsequent cl records on the free list are similarly linked using working set queue pointers the last cl record on the free list has a nil value in its working set queue pointer 60 with respect to storage consumption of the directory structure shown in fig3 in the specific embodiment described herein each cl record manages a band of 256 kbytes of storage device memory as one example if the maximum size of cache memory 32 is 1 gigabyte management of the 4028 256 kbyte bands that may be resident in the cache and an equal number of bands which are not.