iostat---Monitoring IO/CPU performance of Linux

iostat is part of the sysstat utilities which is maintained by Sebastien Godard.

sysstat is open source software written in C.

other utilities in the sysstat package include mpstat, pidstat, sar, nfsiostat, and cifsiostat.

refer to http://www.pythian.com/blog/basic-io-monitoring-on-linux/

1. sysstat download link:

http://sebastien.godard.pagesperso-orange.fr/download.html

2. install with yum

#yum install sysstat

3. usage

#iostat -txkN 120 >> statistic.txt

-t //include a timestamp

-x //more details

-k //specify kB or mB per second

-N //more readable7.49 0.23 7.85 0.20 0.06

Output as below:
-------------------
Linux 3.10.0-123.el7.x86_64 (archs22h8432.tuc.stglabs.ibm.com)  10/26/2014      _x86_64_        (16 CPU)

10/26/2014 07:33:21 PM
avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           0.92    0.00    1.54    0.06    0.00   97.48

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
sda               0.00     0.00    0.15    0.78     0.58   183.66   398.66     0.02   18.76    0.14   22.24   0.46   0.04
sdb               0.00     0.00    0.18    0.74     0.73   166.00   360.92     0.02   17.76    0.12   22.11   0.43   0.04
sdc               0.00     0.00    0.15    0.74     0.58   166.42   376.49     0.02   22.34    0.13   26.72   0.74   0.07
sde               0.00     0.00    0.15    2.90     0.58   179.59   118.39     0.01    2.24    0.15    2.35   0.12   0.04
sdg               0.00     0.00    0.15    0.78     0.58   181.21   393.36     0.02   18.19    0.13   21.57   0.51   0.05
sdf               0.00     0.00    0.15    2.91     0.58   184.89   121.36     0.02    7.49    0.23    7.85   0.20   0.06

注：开头首次显示的是自系统启动开始的平均值，后面显示的是每段时间间隔里的平均值。

http://www.cnblogs.com/bangerlee/articles/2547161.html
http://blog.chinaunix.net/uid-116213-id-484250.html
http://huoding.com/2011/07/13/91