Linux host slows to crawl when ram 20% and 8 core cpu at 99% using virtual machine

Question

I built a new Linux machine to be able to handle multitasking and running multiple virtual machines. It's an AMD 8 core 3.5GHz processor with 16MB Total Cache, 16GB 1866 DDR3 RAM, 1TB HD and a GForce GT 730 4GB 1600 DDR3 Graphics Card. I have VMware Workstation 12 running with 3 guest machines. Each machine has 1GB RAM, 1 CPU/PROCESS, 512MB Graphics, and over 70% drive space to spare. The guest run fine.

When I check system CPU and RAM usage on my host after my host slows down to a crawl, the CPU usage is at ~99% and ram at ~20%. The system has run with no problems with CPU usage at over 210% (observed using top command) while running 1 guest VM. I haven't had any other problems with the system.

Is there something else I haven't measured that could cause the system to crawl when ram and cpu hasn't been maxed out (other than GPU...see update)?

Update: It looks like this may have been an issue with my Nvidia settings for my graphics card. I changed PowerMizer from 'auto' to 'Maximum Performance' and I'm monitoring with system monitor and the graphics card with nvidia-smi and other GPU monitoring tools mentioned here.

Answer 1

The RAM will always show the percentage allotted to VirtualBox depending on the number of guests running regardless of whether or not the guests are actually using all of the RAM allotted to them. I too have an 8 core AMD cpu, with 32GB ram and 2gb gpu ram, with three vbox guests on a linux host. If all three are running:guest 1 has 8gb ram and 4 cores, gpu = 512; guest 2 has 3gb ram and 2 cores, gpu = 128; guest 3 has 2gb ram and 1 core, gpu = 128. Total 13gb ram (13/32)*100=41%, htop will show 41% ram in use,although technically 41% is not physically being used (unless each vbox guest is maxing out its allotted ram). As for the cpu running 99% and machine crawling, I don't know unless your gpu correction fixed the problem.