Visit my.sonatype.com for documentation on Nexus Repository version 2.
We've had reports of people downloading Nexus Repository 2, installing the server, and then seeing the following exception on startup:
jvm 1 | 2012-03-15 11:44:21.972:WARN:oejw.WebAppContext:Failed startup of context o.e.j.w.WebAppContext{/nexus,file:/opt/download/nexus-2.0.2/nexus/},./nexus
jvm 1 | java.io.IOException: Stream closed.
jvm 1 | at java.util.zip.ZipInputStream.getNextEntry(libgcj.so.10)
We've tracked this down to an incompatible JVM or JRE. If you are using Debian you may be running the GNU Interpreter for Java (gij). Nexus Repository 2 is not tested or qualified with this unsupported Java runtime. If you are experiencing this error, Sonatype recommends that you obtain a JDK or JRE from Oracle. If you are running on an Ubuntu or Debian distribution the current recommendation is to use Sun Java 1.6.
See, the Debian Java page for more information about installing the Sun Java 1.6 JDK or JRE.
Update: This error can occur if GCJ is used to run Nexus Repository 2. GCJ is the default Java on many Redhat/CentOS systems. Use Oracle or OpenJDK on these systems.