The virtual machine image is based on CernVM (cernvm.cern.ch), with Scientific Linux CERN 5 (slc5), which is the environment needed for the CMSSW release to be used with the 2010 CMS open data. It gets the CMS software (CMSSW) from /cvmfs/cms.cern.ch. Access to the data is through XRootD.
The "CMS-OpenData-1.1.4.ova" version is recommended, it has an embedded slc5 shell, where all CMS software specific commands should be executed. Additionally, it has a slc7 shell, which can be used in the same session. It has a 20G virtual hard disk and a 10G cvmfs cache and can read the condition data from /cvmfs/cms-opendata-conddb.cern.ch.
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.