The invention relates to a method for managing a buffer memory space associated with a persistent data storage system of a computing machine. The buffer memory space is suitable for temporarily storing in the RAM of the machine one or more portions of a single data file of the persistent data storage system that was previously accessed by one or more processes executed on the machine. The operating system of the machine tracks each of the portions of the file that are projected in the buffer memory space by a descriptor belonging to a plurality of buffer memory projection descriptors which are all associated with the tracking of one or more portions of the file projected in the buffer memory space.