Transparent handling of small files with dCache to optimize tape access

Abstract

We introduce a service for dCache that allows automatic and transparent packing and extracting of file sets into large container files. This is motivated by the adoption of dCache by new communities that often work with rather small data files which causes large time overheads on reads and writes by the underlying tape systems. Our service can be attached to existing dCache instances and we were show that it is able to optimize average access times to tape access.