Hello, I've written an article about my ongoing work on improving OpenStack's parallel performance: http://blog.gridcentric.com/bid/318277/Boosting-OpenStack-s-Parallel-Performance The article discusses host configuration changes and patches (upstream and in progress) that give a 74% speedup in a parallel macro benchmark (boot 40 instances, ping them, ssh into them, delete them). This article is a follow up to my presentation at the OpenStack summit in Portland. Peter