<u style="display: none;">... no changes ... no changes ... no changes ... no changes ... no changes ... no changes ... no changes ... no changes ... no changes ... no changes ... no changes ... </u><code><code> From: Daniel WyssTo: imp@lists.horde.orgSubject:Subject: RE: [imp] Help Req. : Sizing aHordeIMPHorde\IMP system for 12,000 usersSpeaking from experience combining Sun hardware/Cluster/and Imp/Horde:I would first separate out your web server(s) from your mail and DBserver(s) especially if you plan on using a secure web server and/orIMAPS. For this web server, use your best hardware, you may experiencehigh loads like we did using SSL, so you may also consider purchasingcrypto-cards if you run into this problem. The next (big) step would beto run a scalable apache server (via Sun Cluster 3.0). This startsgetting pretty expensive, cost of licensing Sun Cluster 3.0 software,the cost of agents, the cost of the approved architecture, and the costof support. Plus you definitely want to get some training if you'regoing to run a Sun Cluster. (personally I wouldn't recommend this routeunless you really need HA and/or scalability.) I think option 2 fromEric's message down below might be the sensible route in your situation.Background:We have been running Imp/Horde here at the University of Colorado sincethe Summer of 2000 exclusively on Sun hardware. We initially opened itup to existing students as an alternative option to pine/elm orimaping/popping. The existing students had the choice to migrate overfrom an older mail server to this WebMail system, and all new incomingstudents were giving an account to this newer system. That first Fallsemester we started with 5000 user accounts, and today there are 40k. Westarted off with (1)E3500 with 6 336MHz processors 2Gb of memory whichserved as the mail (IMAP only) and mysql backend. The Front-end webserver was also a E3500 with 6 400MHz processors and 3 Gb of memory.When we hit about 30k user accounts we started experiencing high load onboth servers. Granted, we do add some load with some in-house tweeks tothe IMP/Horde software for quota and affiliation check, as well as doingsecure IMAPS and SSL. We ended up with a soon to be 6 node V480 SunCluster 3.0 system that is running scalable apache serving the front-end(running IMP/Horde). For the backend, I ended up writing an agent forboth mysql and uw-imap and this is in a 2 node cluster running (2) V880(one with 6 ultra-sparc-III 750MHz chips and the other with 8, one has12 GB and the other has 16GB of memory). It's a screaming system now. Ihave had my hands in this since the beginning, so if you want some moreinfo about what we are doing here and what we have learned, feel free tocontact me.******************************************Daniel WyssIT PRO, Central and Unix ServicesInformation Technology ServicesUniversity of Colorado, Boulder3645 Marine St, CB 455Boulder, CO 80309-0455</code>