1. A method of managing a file system cache in a first computer system having a processor, memory and storage means, said file system cache occupying at least two cache areas of said storage means with each cache area having a different cache management policy, the method comprising the steps of: setting a respective first size of each of said cache areas in said storage means; testing the amount of free space in a selected cache area in response to a request to store a file system object in said file system cache, the selected cache area determined by the cache management policy appropriate for a degree to which the file system object should be persistently stored in a memory of a second computer system, the file system object containing at least some data unique to the first computer system; expanding the size of said cache without operator intervention if said testing determines that the free space is less than a first amount.