Question Plesk use soo much RAM and CPU

[shanmuga]

Server operating system version

Ubuntu 20.04 aarch64

Plesk version and microupdate number

Plesk Obsidian 18.0.47.5

Hi,

I have 2 ARM Server of 24 GB RAM and 4 CPU. I have around 6-10 normal website hosted in each of them but plesk consume 80% of RAM and i am not sure what it being used. I checked both plesk on same configuration and both plesk consume similar resource.



Fun facts is, i have another server with 1 CPU, 1GB RAM and AMD processor. It have around 15 website hosted in it and it still have 40% free memory.

Is this problem with Plesk?

 

[shanmuga]

Update :

I have installed Plesk 360 Monitor and here is full report.



What does buffered, cached and inactive mean?

and what is swap and why it say no swap?

 

[Peter Debik]

You are not seeing the RAM consumption of Plesk. RAM usage by Plesk services is neglecticably low. What you are seeing is mostly usage of PHP, Apache, Nginx and your database, and it is looking just fine on your system.

Linux preserves data in RAM beyond what is actively being used. That is just right (it's the buffered and cached part). If a process requests more RAM that is still "free", Linux will clear more RAM from the cache automatically. Your system seems to be doing this perfectly right.

The fact that on your other system you see 40% free RAM is owed to the same behavior of Linux: It sees that there is not enough RAM to cache a lot of stuff, so it doesn't.

Swap: Normally you should have a swap partition on your hard disk that is around half of the RAM size. In your case a swap partition of 16 GB would be good. Just in case that the ordinary RAM is insufficient for all active processes, Linux will then park RAM content on disk and reload it from there if it is needed. It will try to avoid swap usage, because that will slow down the system considerably. Swap is just an option to extend real RAM. A system can do without if there is enough RAM, but it is safer to have a swap partition.