How to use vmstat in Linux system
This article introduces the relevant knowledge of "how to use vmstat in Linux system". Many people will encounter such a dilemma in the operation of actual cases, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!
Vmstat is used to view memory usage in real time, which is more intuitive than using top.
If you use it directly, you can only get the current situation, and it is best to use a time interval to collect it.
Vmstat T in which T is marked with a specific time, in seconds, for example: vmstat 5 form is collected every 5 seconds.
In this way, when refreshing, you can systematically see which column is abnormal.
Procs:
Rmusic->; number of processes waiting in the run queue
BMQ->; number of processes waiting for io
Wmurf->; a process that can enter the run queue but be replaced
Memoy
Swap-- >; currently available swap memory (k for)
Free-- >; free memory (k stands for)
Pages
Re-- "recycled pages"
Mf-- "pages with non-critical errors
Number of pages entered by "pi--" (k represents)
Number of po-- "pages (k stands for)
Fr-- "number of pages free (k stands for)
Number of misses in pages read in advance by de--
Sr-- "pages scanned by clock algorithm
Disk shows disk operations per second. S for sci disk, 0 for disk number
Fault shows the number of interrupts per second
In-- "device interrupt
Sy-- "system interruption
Cy-- "cpu exchange
Cpu indicates the usage status of cpu
Cs-- "time used by user processes
Sy-- "time used by system processes
Id-- "cpu idle time
Where:
If r is often greater than 4 and id is often less than 40, the load on cpu is very heavy.
If pi,po is not equal to 0 for a long time, there is not enough memory.
If disk is often not equal to 0 and the queue in b is greater than 3, it means that io performance is not good.
Example:
The code is as follows:
[root@localhost ~] # vmstat 2 # displays system memory statistics every two seconds
Procs-memory--swap---io-----system---cpu
R b swpd free buff cache si so bi bo in cs us sy id wa
0 0 0 219908 62964 175548 0 0 47 12 12 17 0 1990
00 0 219900 62964 175548 00 00 11 12 00 100 0
00 0 219900 62964 175548 00 00 9900 100 0
The code is as follows:
[root@localhost ~] # vmstat 2 5 # displays system memory statistics every two seconds for a total of 5 times
Procs-memory--swap---io-----system---cpu
R b swpd free buff cache si so bi bo in cs us sy id wa
0 0 0 219908 62964 175548 0 0 46 12 12 17 0 1990
00 0 219900 62964 175548 00 00 12 14 00 100 0
00 0 219900 62964 175548 00 00 11 11 0 1 100 0
00 0 219900 62964 175548 00 00 10 11 00 100 0
00 0 219900 62964 175548 00 00 10 900 100 0
The code is as follows:
[root@localhost ~] # vmstat-d # displays disk information
Disk--reads--writes--IO-
Total merged sectors ms total merged sectors ms cur sec
Ram0 0 0 0
Ram1 0 0 0
Ram2 0 0 0
Ram3 0 0 0
Ram4 0 0 0
Ram5 0 0 0
Ram6 0 0 0
Ram7 0 0 0
Ram8 0 0 0
Ram9 0 0 0
Ram10 0 0 0
Ram11 0 0 0
Ram12 0 0 0
Ram13 0 0 0
Ram14 0 0 0
Ram15 0 0 0
Loop0 0 0 0
Loop1 0 0 0
Loop2 0 0 0
Loop3 0 0 0
Loop4 0 0 0
Loop5 0 0 0
Loop6 0 0 0
Loop7 0 0 0
Sda 12341 5909 471542 465300 1325 2081 127088 32204 0 19
Sr0 0 0 0
This is the end of "how to use vmstat in Linux system". Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!
