You can still allocate more virtual memory; it just has to be backed by a file, e.g., through mmap(). So, for example, what mongod does — mmap() in its entire D

You can still allocate more virtual memory; it just has to be backed by a file, e.g., through mmap(). So, for example, what mongod does — mmap() in its entire DB, which can be terabytes of RAM — would still work. You can almost think of file-backed mmaps as swap, in fact.