So, I've got 2 new Ubuntu 8.04 JeOS VMs running, they're both really lightweight and haven't got much running on them at all, no Apache, MySQL etc etc. Yet they're using 350M of RAM and I cannot see why.
I've taken a look using
ps -auxw --sort rss but can only see your general sshd, bash etc process running and they're not using much memory at all.
top shows 99.6% idle, so there's nothing CPU intensive running.
free -mt output:
total used free shared buffers cached Mem: 503 350 152 0 111 174 -/+ buffers/cache: 64 438 Swap: 471 0 471 Total: 975 350 624
(Yes, it only has 512MB of RAM for testing purposes.
Edit: I also have several VMs running Ubuntu 9.04 32bit server-edition that are using 20-30M of RAM with almost identical packages installed.