US Patent 11914556 Lazy virtual filesystem instantiation and caching

A host with a memory, which stores a guest, a filesystem cache, and a proxy cache, has a filesystem manager executing on a processor that receives a first request to locate a file in a first filesystem. In response to receiving the first request, a filesystem proxy in the proxy cache associated with the first filesystem is queried. The first request is responded to based on metadata retrieved from the filesystem proxy. A second request is received to modify the file. In response to receiving the second request, the first filesystem is instantiated in the filesystem cache, where a second filesystem is evicted from the filesystem cache to reclaim storage capacity for the first filesystem. The file in the first filesystem is modified.