Details about vmstat Command Parameters

Vmstat n m: refresh every n seconds, and exit after capturing M.

[Oracle @ sor-sys properties] $ vmstat 2 3
Procs ----------- memory ---------- --- swap -- ----- Io ---- System -- ----- CPU ------
R B SWPD free buff cache Si so Bi Bo in CS us Sy ID wa st
0 0 96 655968 278912 2117884 0 0 0 10 1 1 18 2 80 0 0
1 0 96 655968 278912 2117884 0 0 0 1011 0 0 694 0 0 0
0 0 96 655968 278912 2117884 0 0 0 34 1013 0 0 338 0

Field description for VM Mode

Procs
R:
Number of processes waiting for run time. Number of kernel threads in the running Queue (number of processes ).
B:
Number of processes in uninterruptible sleep. Number of kernel threads placed in the waiting queue (waiting for resources, waiting for input/output. Number of uninterruptible processes in the block queue

Memory
SWPD: The amount of virtual memory used.
Available virtual swap memory
Free: The amount of idle memory.
Idle memory
Buff: The amount of memory used as buffers.
Buffer Used
Cache: The amount of memory used as cache.
Cache used
Inact: The amount of inactive memory. (-A option)
Amount of inactive memory
Active: The amount of active memory. (-A option)
Active memory count

Swap
Si:
Amount of memory swapped in from disk (/s). Number of switching pages from disk to memory (Unit/s)
So:
Amount of memory swapped to disk (/s). Number of switching pages from swap memory to disk (Unit/s)

Io
Bi: Blocks
Received ed from a block device (blocks/s). number of blocks received by the block device (Block/s)
Bo: Blocks sent to a block device (blocks/s ).
Number of blocks sent to the block device (Block/second)

System
In:
Number of interrupts per second, including the clock. Number of interrupts per second, including clock interruptions
CS: The number of context switches per second.
Context switches per second

CPU
These are percentages of total CPU time.
Us: Time spent running non-kernel code. (user time, including
Nice time) percentage of time when the user time is in user mode
Sy: Time spent running kernel code. (System Time)
Percentage of time when the system time is in kernel mode
ID: Time spent idle. Prior to Linux 2.5.41, this includes des
Io-wait time. Percentage of idle CPU time
Wa: Time spent waiting for Io. Prior to Linux 2.5.41, sorted DED
In idle. CPU idle time during which the system has unfinished Disk/nfs I/O requests
St: Time stolen from a virtual machine. Prior to Linux
2.6.11, unknown. Percentage of CPU stolen from the VM (this will not translate ...)

Field
Description for disk Mode
Reads
Total: Total reads completed successfully
Merged: Grouped reads (resulting in one I/O)
Sectors: Sectors Read successfully
MS: milliseconds spent reading

Writes
Total: Total writes completed successfully
Merged: Grouped writes (resulting in one I/O)
Sectors: Sectors written successfully
MS: milliseconds spent writing

Io
Cur: I/O
In progress

S: Seconds spent for I/O

Bytes ----------------------------------------------------------------------------------------------------------

Notice:

Procs R: many processes are running and the system is busy.

Bi/Bo: the volume of data written to the disk is a little large. If it is a large file, you don't have to worry about writing within 10 MB. If it is a small file, writing within 2 Mb is basically normal.

CPU us: it lasts for more than 50% and is acceptable during peak service hours. If it is longer than 50, you can consider optimization.

CPU Sy: Percentage of actual kernel processes. Here, the reference value of US + Sy is 80%. If US + Sy is greater than 80%, there may be insufficient CPU.

CPU Wa: the percentage of CPU time occupied by Io wait is displayed in the column. The reference value of WA is 30%. If wa exceeds 30%, the IO wait is serious, which may be caused by a large number of random access to the disk,
It may also be caused by the bandwidth bottleneck of the disk or disk access controller (mainly block operations ).

Cpu id: the percentage of idle CPU is usually less than 50, which is acceptable during peak service hours.