The Rome CMS Tier2 regional centre, hosted by INFN, moved to its new location in December 2007. A new hall was built for the centre, as well as for the ATLAS Tier2 centre.
CMS computing is a distributed activity, organized in a multi-Tier hierarchical structure. Data are processed at the Tier0 centre at CERN, then shipped to Tier1 centres via high-speed networks. These provide CPUs for data reprocessing and simulations, and archive data on tapes. Part of the data is then copied to Tier2 centres, where Grid services automatically dispatch jobs submitted by physicists.
The INFN Rome Tier2 centre is equipped with four water-cooled racks made by German company Knuerr. Three more racks will have been installed in March 2008, but the hall can host up to 14 racks. Racks are fed by water stored in a three cubic metre reservoir and chilled to 12 degrees. Water enters heat exchangers inside the racks, cooling hot air produced by the CPUs, and exits the rack at 18 degrees. Such a modular technology allows for a reduction of electrical power and temperature stability, keeping the hall at room temperature.
The centre is equipped with tools for remote operations and monitoring, as well as security devices such as fire and flood sensors. Potentially catastrophic events generate automatic emergency procedures, and in case of power failure we are able to automatically shut down the machines cleanly, thanks to the Uninterrupted Power Supply (UPS). Any event is logged and notified to administrators via e-mail, and SMS notification is coming soon.
This article was published online in the CMS Times on 18 February (http://cmsinfo.cern.ch/outreach/CMSTimes.html).
Luciano Barone and Giovanni Organtini, PH Department