vmstat 解析

 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.