Correctly determining memory usage in Linux
I see that almost all my RAM is in use. Is this bad? Strange thing is I don't see what is actually using the RAM.
No problem in that. Linux is borrowing the RAM for caching. This is desirable (RAM is faster than disk) and absolutely normal behaviour.
From that link:
To see how much RAM you have free, type
Thus I'm using about 1.5 GB RAM, not 4 GB as the first line might make it look like.
Its mostly linux caching data. If you use