Hello, We are hosting 3000+ webs/dbs on a single server, and are running into some OS-level limits (like max open file descriptors, semaphores, ...). Splitting over multiple servers is not an option for the moment. It's not a problem with ISPConfig but I was wondering if there are other people here who have run into the same, and have some pointers/docs/guides for optimizing such limits.
You should limit or merge log files, for example. If you merge error and access file or you disable them, you can save resources. Disable php support for websites that does not need it.