vmstat可以用来查看系统性能，这个没什么好说的，但google了一下，结果很少，还有chinaunix02年的帖子
其实 man vmstat 上面说的清清楚楚
一.vmstat -n 1 3
[root@localhost monitor]# vmstat -n 1 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 0 174308 108384 524816 0 0 13 12 664 141 1 4 94 1 0
0 0 0 174300 108384 524816 0 0 0 0 646 122 4 4 92 0 0
0 0 0 174300 108384 524816 0 0 0 0 967 512 14 9 77 0 0
二.下面是 摘抄的man vmstat 很少的一部分
FIELD DESCRIPTION FOR VM MODE
Procs
r: The number of processes waiting for run time. 运行进程个数
b: The number of processes in uninterruptible sleep. 阻塞进程个数
Memory
swpd: the amount of virtual memory used. 使用的虚拟内存
free: the amount of idle memory. 空闲内存
buff: the amount of memory used as buffers. buffers 用于写操作的缓存
cache: the amount of memory used as cache. cache 用于读操作的缓存
inact: the amount of inactive memory. (-a option)
active: the amount of active memory. (-a option)
Swap
si: Amount of memory swapped in from disk (/s). 从磁盘换入内存的大小
so: Amount of memory swapped to disk (/s). 换出到磁盘的大小
IO
bi: Blocks received from a block device (blocks/s). 从磁盘读的块数
bo: Blocks sent to a block device (blocks/s).
System
in: The number of interrupts per second, including the clock. 每秒中断次数
cs: The number of context switches per second. 每秒上下文切换数(可理解为进程切换数)
CPU
These are percentages of total CPU time.
us: Time spent running non-kernel code. (user time, including nice time) 非内核代码所占cpu百分比，用户占用
sy: Time spent running kernel code. (system time) 内核代码占用cpu百分比，系统占用
id: Time spent idle. Prior to Linux 2.5.41, this includes IO-wait time. 空闲cpu百分比
wa: Time spent waiting for IO. Prior to Linux 2.5.41, included in idle. 等待I/O所花的时间
st: Time stolen from a virtual machine. Prior to Linux 2.6.11, unknown.
声明：本文档可以随意更改，但必须署名原作者
作者：凤凰舞者 qq:578989855
