vmstat——系统性能监测工具

DESCRIPTION

       vmstat  reports  information about processes, memory, paging, block IO,

       traps, and cpu activity.

       The first report produced gives averages since the last reboot.   Addi-

       tional  reports  give information on a sampling period of length delay.

       The process and memory reports are instantaneous in either case.

用法：

   vmstat [-a] [-n] [delay [ count]]

       vmstat [-f] [-s] [-m]

       vmstat [-S unit]

       vmstat [-d]

       vmstat [-p disk partition]

       vmstat [-V]

NOTES

       vmstat does not require special permissions.

       These  reports are intended to help identify system bottlenecks.  Linux vmstat does not count itself as a running process.

       All linux blocks are currently 1024 bytes. Old kernels may report blocks as 512  bytes,  2048  bytes,  or

       4096 bytes.

       Since  procps  3.1.9,  vmstat lets you choose units (k, K, m, M) default is K (1024 bytes) in the default mode

       vmstat uses slabinfo 1.1    FIXME

FIELD DESCRIPTION FOR VM MODE

   Procs

       r: The number of processes waiting for run time.

       b: The number of processes in uninterruptible sleep.

   Memory

       swpd: the amount of virtual memory used.

       free: the amount of idle memory.

       buff: the amount of memory used as buffers.

       cache: the amount of memory used as cache.

       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).

       so: Amount of memory swapped to disk (/s).

   IO

       bi: Blocks received from a block device (blocks/s).

       bo: Blocks sent to a block device (blocks/s).

   System

       in: The number of interrupts per second, including the clock.

       cs: The number of context switches per second.

   CPU

       These are percentages of total CPU time.

       us: Time spent running non-kernel code. (user time, including nice time)

       sy: Time spent running kernel code. (system time)

       id: Time spent idle. Prior to Linux 2.5.41, this includes IO-wait time.

       wa: Time spent waiting for IO. Prior to Linux 2.5.41, included in idle.

       st: Time stolen from a virtual machine. Prior to Linux 2.6.11, unknown.