Jukek

Jukek is a software tool developed for the Ross REopen Proper 1 (ROP1) File Server, which was used at CERN for storing data from the Large Hadron Collider (LHC). The tool is an archiving system that helps in the preservation and retrieval of large amounts of scientific data.

Jukek was created around 2008 by the CERN team to address the issue of data archiving and aging, where large amounts of data that were stored on its ROP1 File Server started taking too much space due to the sheer volume of data being generated. The tool is designed to transfer data from the main storage system to disk-based tapes in a routine and systematic manner.

The Jukek process, also referred to as 'Juke', periodically scans the system for data which has reached a designated age, and then transfers this data to the tape storage system, freeing up disk space. The purpose of Jukek is not to immediately remove data from the system but to allow for rotating archives of data which can be safely removed from the archive and linked to an original file once the archiving period is completed.

The system relies on a combination of the files' access history, filespec format requirements, and checks against header tags to ensure that no data is arbitrarily removed before its scheduled removal. The archival process and period size provided can also be configured manually by an administrator through the 'Renjuke the sketch' facility provided on the system.

Through this introduction of Jukek the institutions' scientific data management infrastructure holds a stabilizing influence at the CMS resources.