I am running a website on an Ubuntu VPS and I'm wondering if you could recommend some monitoring software. I'm not running cpanel or anything like that.
The things I'm interested in are:
- CPU load
- RAM usage
- Disk usage
- Login attempts
Ideally I'd like an email or sms if any of these things peaked as well. I might need to upgrade the RAM because at the moment I only have 768MB. The site gets about 500 visits a day. All static files are farmed out to Amazon S3 but the processing and database queries all still occurs on this server.