Trying to understand web-server performance bottleneck

Hi guys,

I have a local server running on CentOS 7 (CWP pro). It's primarily used as a web-server (PHP/FPM + MariaDB)

Hardware specs

  • Intel Xeon E5-2689 @ 2.60GHz x 16 Cores
  • 12GB of DDR3 RAM
  • 100GB of NVME storage
  • 1Gb/s ethernet connection

Currently there is 1 website hosted (WooCommerce) and it feels pretty slow when I try to open multiple web pages at once without serer-side cache. While the pages load slowly, CPU / RAM / SSD usage do not seem to be high at all. (according to CWP, CPU never goes over 20%, RAM never goes over 30%)

I've run a few commands to check resource usage, but I'm still very confused about where the bottleneck is.

Can someone please look at these logs and point me in the right direction? Or tell me if I should run some other command to find the issue.

Thanks

Logs -

command: top

command: mpstat -P ALL 1

command: vmstat 1

command: iostat -m 2