Java HotSpot(TM) Server VM warning: increase O_BUFLEN in ostream.hpp -- output truncated

[John Rose]

Your best bet is to wait for 6912062 to integrate to jdk7/hotspot and become part of the periodic builds.  It's in hotspot/hotspot right now:
  http://hg.openjdk.java.net/jdk7/hotspot/hotspot/rev/4e6abf09f540

That garbage output looks like it might be from a product build; try using a debug build if you can find one.

-- John