Eric Déchaux <Eric.Dechaux@xxxxxxx> wrote: > The older infrastructure can stand the 42 000 concurrent sessions, the> new one can't : I was expecting each frontend to be able to handle 5 500> concurrent sessions but they are not. Around 3 000 / 3 500 concurrent> sessions the frontends begin to SWAP and are not more able keep up the> load. Did I undertand correctly: You are virtualizing each component and your frontends begin to swap in their virtual environment?Is there any reason why you don't assign more RAM to them? Does your frontend virtual machines run a 64 bit kernel? We abandoned all Linux for our Cyrus Servers and switched to Solaris 10 with Zoning and ZFS. We have less concurrent users than you but more storage (10 T at the moment). ----Cyrus Home Page: http://cyrusimap.web.cmu.edu/Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twikiList Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html