Hi guys, I've got an ISPConfig 'the perfect server' on Ubuntu 14.04, and I spent the weekend setting up Monin and Munit for it according to the tutorial on this site. Everything was fine for a couple of days, but recently (yesterday & today) I can no longer access any of my sites - every port comes up connection refused (ssh, ftp, smtp and http). Yesterday I was able to fix the problem with a restart. Today, that doesn't work. dmesg reports a segmentation fault in php-cgi, and I know clam and amavis are struggling with the amount of RAM (2GB) and crashing at times. I've been looking into ways of reducing memory usage, we've only got a half-dozen sites so shouldn't need much more resource. Not sure if this is relevant. Any assistance appreciated. I rely on this server for my business. So far no work today - and this isn't good. Thanks in advance.
You'll probably get some better ideas, but a few thoughts: Do you have any swap space? I'd expect you could live reasonably well with 2GB, and a little (maybe another 2G) swap. Make sure mysql doesn't grow too large. Turn anything off you don't use, eg. php-fpm daemon if you're using fastcgi mode and spamd. Maybe run fewer amavisd children. See what apache modules you have loaded and turn some off if not needed (eg. ruby/passenger, python and memcache might be candidates). And see what all processes are running and make sure nothing is gone awry.
I have a swapfile set at 2GB also. I'd considered 4GB, but it's not using all of the swapfile. Maybe I need to increase the 'swappiness'. I think it's MySQL bloating that causes the problem, but need to do more research. Happily, I found the lockouts were caused by an error in Fail2Ban, which I have fixed by whitelisting my IP.