Great list with "standard" tools that you'd find on most systems by default. From my experience for virtualized servers you might also look at: - system and st

Great list with "standard" tools that you'd find on most systems by default. From my experience for virtualized servers you might also look at: - system and stolen cpu to show virtualization overhead and VMs starvation for CPU (in vmstat) - interrupts and context switches which might indicate that VMs might be running non-optimized OSs or non-paravirtualized drivers (vmstat) - abusing VMs/Containers (platform specific), ie for KVM: virsh vcpuinf, virsh dominfo - socket summary and dig from there: ss -s