Linux Performance Testing Tool Vmstat command

The Vmstat command of the Linux Performance Testing Tool monitors the process, memory, page I/O blocks, CPU, and other information. vmstat can display the average value or sample value of the testing results, the sampling mode provides monitoring results at different frequencies within a sampling period.

Linux Performance Testing Tool Vmstat command processprocs)
R: Number of processes waiting for running time
B: Processes in non-disruptive sleep state
W: process that is switched out but can still run. The value is calculated.

· Linux Performance Testing Tool Vmstat command memoryswpd: Number of virtual memory
Free: Number of idle memory
Buff: The amount of memory used as a buffer

Linux Performance Testing Tool Vmstat command-swap
Si: Number of switches from hard disk
So: Number of switches to the hard disk

Linux Performance Testing Tool Vmstat command · IO
Bi: number of blocks output to a block Device
Bo: number of blocks received from a device

Linux Performance Testing Tool Vmstat Command system
In: number of interruptions per second, including clock
Cs: Number of context switches occurring per second

· Linux Performance Testing Tool Vmstat command cpu (percentage of cpu running time)
Us: User time for running non-kernel code, including nice time)
Sy: kernel code running time system time)
Id: idle time. In kernel versions earlier than Linux 2.5.41, this value includes the I/O wait time;
Wa: The time for waiting for I/O operations. In Linux versions earlier than 2.5.41, this value is 0.

The Vmstat command provides a large number of additional parameters. The following lists several useful parameters:
Reference
· M: displays the memory usage of the kernel.
· A: displays the memory page information, including active and inactive memory pages.
· N: Display header lines. This parameter is useful when sampling mode is used and command results are output to a file. For example, root # vmstat-n 2 10 displays 10 output results at a frequency of 2 seconds.
· When-p {partition} is used, vmstat provides statistics on the I/O results