100% memory usage in Debian 8 + VestaCP?

Question

Debian

Hello, the server has debian 8 + vestacp installed, 4GB of RAM.
According to the graphs of the news - the memory is 100% occupied.
is this normal at all?
and it did not happen right away, but on the second day after installing the system on iron.
The same picture on another server, but there 100% memory loading started after 2 months of using the server. This is suspicious. Or deb. Does it use memory (all installed) or am I broken?
How to understand what is happening?
(According to the logs of Exim, the number of letters is normal.)
Or maybe it's in the news?

Answer 1

Be careful how busy you are. Applications or used in total.
Because linuxatemyram.ru