This paper presents a classification of file placement and replication methods on grids. The study is motivated by file transfer issues encountered in the Virtual Imaging Platform deployed on the European Grid Infrastructure. Approaches proposed in the last 6 years are classified using taxonomies of replication process, replication optimization, file models, resource models and replication validation. Most existing approaches implement file replication as a middleware service, using dynamic strategies. Production approaches are slightly different than works evaluated in simulation or in controlled conditions which (i) mostly assumes simplistic file models (undistinguished read-only files), (ii) rely on elaborated access patterns, (iii) assume clairvoyance of the infrastructure parameters and (iv) study file availability less than other metrics but insist on cost. ► We propose a classification of file replication and placement methods on grids. ► We review works published during the past 6 years. ► We highlight singularities of approaches deployed in production.