After start up, ypserv seems to consume memory in ever increasing amounts.
After a while, it will take up so much memory that it and other services
will begin dying off.

From top:

  PID USER     PRI  NI  SIZE  RSS SHARE STAT  LIB %CPU %MEM   TIME COMMAND
14119 root      11   0 17308  16M   496 S       0 10.3 13.5  43:59 ypserv

I'm told that ypserv should typically not take up more than about 2-3MB of
memory.