After upgrading to ws-cleanup 0.24 in order to get the asynchronous cleanup function we noticed the workspaces on our slaves getting renamed to the form of ${WORKSPACE}ws-cleanup${TIMESTAMP}. (ie, job1 would become job1_ws-cleanup_1411197183394). The expected behavior under ws-cleanup 0.24 is that these were temporary to support asynchronous processing and would be deleted. However, these directories never get removed from the slave. Over time, the slave hard drives filled up resulting in build failures.