Conceptually, fast server-side page cache storage could dramatically reduce paging I/O. In this extended abstract, we speculate how such a device might be used, then show how it can be implemented virtually in a hypervisor. We then introduce hcache (pronounced "aitch-cash"), our prototype implementation built on the Xen hypervisor and utilized by slightly modified Linux paravirtualized domains. We discuss the implementation and the current status of hcache, present some performance results, compare it to related work, and conclude with some speculation of other possible uses for hcache.
Daniel J. Magenheimer, Chris Mason, Dave McCracken