Popular interview question: how to diagnose a mysterious process that’s taking too much CPU, memory, IO, etc?
The diagram above illustrates helpful tools in a Linux system.
‘vmstat’ – reports information about processes, memory, paging, block IO, traps, and CPU activity.
‘iostat’ – reports CPU and input/output statistics of the system.
‘netstat’ – displays statistical data related to IP, TCP, UDP, and ICMP protocols.
‘lsof’ – lists open files of the current system.
‘pidstat’ – monitors the utilization of system resources by all or specified processes, including CPU, memory, device IO, task switching, threads, etc.