Tape storage remains the most cost-effective system for safe long-term storage of petabytes of data and reliably accessing it on demand. It has long been widely used by Tier-1 centers in WLCG. GridKa uses tape storage systems for LHC and non-LHC HEP experiments. The performance requirements on the tape storage systems are increasing every year, creating an increasing number of challenges in providing a scalable and reliable system. Therefore, providing high-performance, scalable and reliable tape storage systems is a top priority for Tier-1 centers in WLCG. At GridKa, various performance tests were recently done to investigate the existence of bottlenecks in the tape storage setup. As a result, several bottlenecks were identified and resolved, leading to a significant improvement in the overall tape storage performance. These results were achieved in a test environment and introduction of these achievements in to the production environment required a great effort, among many other things, a new software had to be developed to interact with the tape management software. This contribution provides detailed information on the latest improvements and changes on the GridKa tape storage setup.

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This paper explores the methods and results confirming the baseline assumption that LHCONE[1] (Large Hadron Collider Open Network Environment) traffic is science traffic. The LHCONE is a network conceived to support globally distributed collaborative science. LHCONE connects thousands of researchers to Large Hadron Collider (LHC) datasets at hundreds of universities and labs performing analysis within the global collaboration on high-energy physics. It is “Open” to all levels of the LHC as well as a short list of approved non-LHC science collaborations. LHCONE satisfies the need for a high performance global data transfer network of supporting scientific analysis. Even though LHCONE is a closed virtual private network, packets from non-LHCONE sites were found within the network on multiple occasions. This paper describes the findings, discusses the reasons and proposes some ideas on how to prevent “unroutable LHCONE packets” in order to maintain trust and integrity within the network.