Enhancing data integrity and resilience: Extending the CERN backup system with a tape-based backend

Abstract

The CERN IT Department is responsible for ensuring the integrity and security of data stored in the IT Storage Services. General storage backends such as EOS, CERNBox and CephFS are used to store data for a wide range of use cases for all stakeholders at CERN, including experiment project spaces and user home directories. In recent years a backup system, cback, was developed based on the open source backup program restic. cback is currently used to backup about 2.5 billion files and 18PB stored on disks in the CERN Computing Center. To significantly increase the reliability and security of the backups and reduce the storage costs, by limiting the amount of data on disk, we have added a tape storage backend to cback. With this addition cback can reliably be extended to new use cases, like backing up any local mountable file system, such as EOS, CephFS, NFS or DFS. In this paper we will describe the architecture and implementation of cback with the new tape storage backend and a number of developments planned for the near future.