I plan to launch an app, and plan to set its available memory optimistically high (it's a VPS). How can I figure out, say looking a month later, what it's maximum usage over that time was, i.e. if it ever came near to swapping memory? Thanks in advance for any feedback.
4 Answers
There's the old standby, sar (sysstat/sa1). It can give you all sorts of useful statistics including memory and cpu utilization, disk io, etc. It's stable, run as a cronjob, and available for pretty much every linux distro.
Install a munin server, and run a munin client on the virtual instance. It will log memory usage and a number of other useful statistists over time.
/proc/user_beancounters