CVMFS: Pushing performance on highly parallel, manycore clients

The CernVM File System (CVMFS) is an efficient distributed, readonly file system that streams software and data on demand. Its main focus is to distribute experiment software and conditions data to the world-wide LHC computing infrastructure. Recent hardware trends have increased the usage of CVMFS in highly parallel environments. Nodes with more than 64 physical cores running concurrent workloads are common. These highly parallel, manycore workloads have exposed specific bugs and limitations of CVMFS in such environments. This contribution reports on the developments that address these issues, and presents new performance benchmarks on machines with 256 (virtual) cores.