Hi our TSM 4.1 Server is hosted on S/390 and we have TSM Clients running on different platforms.All these platforms are connected to ESS. these clients are registered through "managedsyslan" : Number of Managed System for LAN licensed: 221 When or why should I license these managed systems for ESSAPPL or ESSR3APPL ?some of these are already licensed to use TDP for R/3 (R3APPL) !!!!! or is it is just to be able to use the FlashCopy feature on the ESS ?? thanks in advance Ruud van Ruler, Shell Services International BV - ISES/31 Our Data Storage Management home page: http://sww2.shell.com/os390/ > Room 1B/G01 > Dokter van Zeelandstraat 1, 2285 BD Leidschendam NL Tel : +31 (0)70 - 3034644, Fax 4012 Mobile +31(0)6-55127646 Email Internet: [EMAIL PROTECTED] [EMAIL PROTECTED] R.vanRuler