Long-term preservation of analysis software environment

Long-term preservation of scientific data represents a challenge to experiments, especially regarding the analysis software. Preserving data is not enough, the full software and hardware environment is needed. Virtual machines (VMs) make it possible to preserve hardware in software. A complete infrastructure package has been developed for easy deployment and management of VMs, based on CERN virtual machine (CernVM). Further, a HTTP-based file system, CernVM file system (CVMFS), is used for the distribution of the software. It is possible to process data with any given software version, and a matching, regenerated VM version. A point-and-click web user interface is being developed for setting up the complete processing chain, including VM and software versions, number and type of processing nodes, and the particular type of analysis and data. This paradigm also allows for distributed cloud-computing on private and public clouds, for both legacy and contemporary experiments.