This virtual machine image provides CMS computing environment to be used with the 2011 and 2012 CMS open data. The virtual machine is based on the CernVM (cernvm.cern.ch) and uses Scientific Linux CERN. The image gets the CMS software (CMSSW) from /cvmfs/cms.cern.ch and the jobs running on the CMS open data VM read the condition data from /cvmfs/cms-opendata-conddb.cern.ch. Access to the data is through XRootD.
CMS-OpenData-1.5.2.ova is recommended. It has a 40G virtual hard disk and a 20G cvmfs cache, which is large enough for condition data for full event range for 2012 data (see the CMS guide to the condition database for further details). It has an embedded CERN Scientific Linux 6 (slc6) shell, where all CMS software specific commands should be executed. Additionally, it has a CERN CentOS 7 (cc7) shell, which can be used in the same session.
The versions earlier than CMS-OpenData-1.5.2.ova are deprecated; please use the latest available version.
For known issues and limitations see
The contextualisation scripts used for setting up the CMS VM images are available at
A validation report of the CMS VM can be found at
Please follow the tutorial on how to use the CMS Virtual Machine
The open data are released under the Creative Commons CC0 waiver. Neither CMS nor CERN endorse any works, scientific or otherwise, produced using these data. All releases will have a unique DOI that you are requested to cite in any applications or publications.