The gemini search engine that I am using locks up the whole host every time it rebuilds its index.
It is currently on a 24 hour cycle of crawl and rebuild.
The software is from geminispace.info, I call the software Gemini Universal Search, or GUS for short.
I think I am going to have to either stop the search engine entirely, and give up on the service, or, put it on another box, so that its charming behaviour of eating all the resources it can will lock up that box and not this one.