* Another important thing about Unter was that it *proved* that disk basing wasn't a dog. Why? Because it kept extensive statistics about the behavior of its caching code. This permitted one to quickly tell how many times the cache handled a request, rather than having to go to disk. (Generally in an average Unter, 95% of the objects are pulled from cache. Long-running Unters that have done millions of cache fetches have only done in the low tens of thousands of real disk reads).
A well-tuned caching disk-based MUD is *MUCH* faster than a MUD that keeps everything in memory, since it doesn't "page thrash" the host computer as badly. -mjr