I've recently imported a fairly large vB forum to Xen, and I would like some advice on configuration. Stats: 1-3000 online (5000 on weekends back on vB) ~1m threads ~2m members ~70GB attachments ~6GB db size 2 Servers, Server 1 just points at Server 2 (they're on the same subnet) in config.php NB: I tried on just one server, and there just weren't enough resources Server 1: Windows Server, IIS 7.5, PHP 5.3 E3-1240 v2 16GB RAM SATA HDD 1Gb unmetered Server 2: Windows Server, MySQL 5.5 E3-1240 v2 16GB RAM SATA HDD 1Gb unmetered my.ini looks a little like this: Right now it's about a day since the import, and performance is inconsistent. It seemed to be working rather well for a few hours, albeit with constant errors in the error log, and now it's crawling. Periodically, the site just stops connecting to the MySQL server (it's still pingable) and then connects again. Am I missing anything glaringly obvious for the config? UPDATE: it was an addon causing the mysql drops mentioned before, now it's just a case of tuning a stable-ish forum with a few quirks yet to be ironed out.