Using Vmstat to monitor the overall performance of Linux systems

Vmstat is a fairly comprehensive profiling tool that can be used to observe the system's process state, memory usage,

Performance information such as virtual memory usage, disk I/O, System interrupts, context switches, CPU usage, and so on.

Main usage:

Vmstat Delay Count

Where delay is the time interval of the output, count is the number of times the output

For example:

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Description of each parameter in each performance field:

Procs:

R: Number of processes waiting to run

B: Number of processes in non-disruptive sleep state

Memory

SWPD: The amount of virtual memory used, in kilobytes

Free: idle memory, in kilobytes

Buff: Used as the cached memory in kilobytes

Cache: Used as cached memory in kilobytes

Swap

Si: Number of swap pages from disk swap to memory, in kilobytes

So: the number of swap pages from memory swap to hard disk, in kilobytes

Io:

BI: The number of blocks received from a block device, in units of blocks

Bo: The number of blocks sent to a block device, in units of blocks

System

In: Number of interrupts per second, including clock interrupts

CS: The number of environment (context) switches per second

Cpu:

Display as a percentage of total CPU time

US: User CPU time, including nice times (non-kernel code executed)

SY: System CPU Time (kernel code is executed)

ID:CPU idle time, including i/o-wait time

WA:I/O wait time, including during idle time

Note: In standard cases, the values for R and B should be:

R<5,b≈0

Suppose the output is in the information:

R is often greater than 3 or 4, the cut ID is often less than 50%, indicating that the CPU load is very heavy;

Bi, bo long not equal to 0, indicating insufficient memory;

Disk is often not equal to 0, and the queue in B is greater than 2 or 3, indicating poor performance of I/O.

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Using Vmstat to monitor the overall performance of Linux systems