A procedure for operating a server (SERV) that supplies subscribers with data streams of different contents (CONT1 to CONT3), as well as a server and a control unit for executing the procedure. The contents (CONT1 to CONT3) are each stored in a memory unit or in several memory units of the server, and in order to supply a subscriber (SUB1 to SUB8) with a data stream of a particular content, the particular content is read out from the memory unit or from one of the memory units in which the content is stored, and sent to the subscriber as a data stream. A Busy list is set up for each of the contents (CONT1 to CONT3) stored in the memory units (DSD1 to DSD5) of the server (SERV). Each memory unit (DSD1 to DSD4) in which a content is stored, is allocated to the Busy list of the content stored in it. Each memory unit (DSD5) that is not at that time needed for supplying a subscriber, is allocated to a Free list. If a further memory unit is needed in order to supply subscriber with a particular content, a memory unit allocated to the Free list is selected for this purpose, and it is first attempted to select a memory unit allocated to the Free list that is also allocated to the Busy list of the particular content.