[http://www.unixservice.com/ Unixservice] provides SLAs for critical internet infrastructure provisioning. As we have grown over the past 10 years we have become fervent advocates of running such services on a grid/cluster of OpenVZ (or Virtuozzo) servers. The main R&D team leader has just released our own C based unxsVZ grid/cluster manager (unxsVZ) released under a GPL license , including advanced computer science [http://openisp.net/openisp/unxsVZ/wiki/UBCAutonomics autonomic functions ] that we have developed based on discrete mathematics and CMU/IBM research in the field. [http://openisp.net/openisp/unxsVZ unxsVZ source, yum repository and RPMs here.] Call us now with questions; we even provide free deployment support and container tuning support for DNS/BIND, RADIUS, HTTP Apache hosting, ESMTP stores, ESMTP out and MX edge server farms on large VZ grids.