To investigate the usage of disk memory

Check the disk usage. It was confirmed command in CentOS on Vagrant + Virtualbox.

$ df

Check the usage of memory.

$ free

Survey the load on the CPU and disk I / O

Check the load average.

$ uptime

$ w

Check and load average / task status / memory usage / swap.

$ top

CPU and I / O load, and other various confirmation.

$ sar

Check the status of the virtual memory.

$ vmstat

Check the status of the disk I / O.

$ iostat

Check the process running. CPU load of each process, it can confirm the memory usage.

$ ps aux

Display the network-related statistics

$ netstat -an | wc -l