a lot of ram memory used

I am moving from a vps (vistual private server) to a vds (virtual dedicated server) at a low cost but with more resources, the ram was 8G it went to 10G but ...

on the VPS cwp with all my sites installed used about 3G of ram now on the VDS with half of the sites installed (I'm still migrating) I'm using 7.5-8G, I tried to stop ClamAV, Amavis and SpamAssassin services and this initially reduced the ram used by 2G but slowly increased and now they are still at 7.5G of ram occupied with consequent email warnings for few available resources.

I also tried to disable varnish but the result doesn't change.

I can't understand what may have happened, does anyone have any ideas about it?

thanks!

try to check this article :
https://www.linuxatemyram.com/

I have read it many times but it is not my case, where my system also uses a lot of swap and my mailbox is flooded with emails that tell me that I have run out of ram

Try to talk to a system administrator. I do not think somebody on forum will be able to help