Being able to separate the build/archive directory structure from the configuration structure was discussed sometime back. A Jira was created and apparently in Jenkins 1.421. This sounded very useful.
The current changelog says for release 1.421: Allow build directories and workspace directories in $JENKINS_HOME to be placed elsewhere. (issue 8446) And Issues 8446 calls this "'builds' directory in a separate location?" and is marked as resolved. I have spent sometime trying to find any docs on this and how to use it but I just can't seem to get it to do anything. I have tried setting the environment variables "HUDSON_BUILDS" and "JENKINS_BUILDS" but whatever I do nothing different happens. Does anyone know how to use these or can point me to docs on the subject.