Linux iotop工具简介、安装、使用

iotop的简介:

iotop是一款开源、免费的用来监控磁盘I/O使用状况的类似top命令的工具,iotop可以监控进程的I/O信息。它是Python语言编写的,与iostat工具比较,iostat是系统级别的IO监控,而iotop是进程级别IO监控。目前最新的版本为iotop 0.6。其官方网址http://guichaz.free.fr/iotop/

 

iotop的安装:

 

注意,iotop的安装有前提条件(如果操作系统不满足这些条件,iotop无法正确安装):

 

  1:内核版本为2.6.20或更高版本

  2:Python 2.7或更高的版本

 

官方文档的详细介绍如下:

 

Linux has always been able to show how much I/O was going on (the bi and bo columns of the vmstat 1 command).

Iotop is a Python program with a top like UI used to show of behalf of which process is the I/O going on. It requires Python ≥ 2.7 and a Linux kernel ≥ 2.6.20 with the TASK_DELAY_ACCT CONFIG_TASKSTATS, TASK_IO_ACCOUNTING and CONFIG_VM_EVENT_COUNTERS options on.

 

 

iotopyum安装

 

yum安装是最简单、快捷的。前提条件是你有配置yum的源配置。

[root@DB-Server ~]# python -V
Python 2.7.5
[root@DB-Server ~]# uname -a
Linux DB-Server 3.10.0-862.el7.x86_64 #1 SMP Fri Apr 20 16:44:24 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
[root@DB-Server ~]# 
 
 
[root@DB-Server ~]# yum -y install iotop

 

 

 

iotop的源码安装

wget http://guichaz.free.fr/iotop/files/iotop-0.6.tar.bz2
tar -xvf iotop-0.6.tar.gz 
cd iotop-0.6
python setup.py build
python setup.py install

 

 

 

iotop的参数

# iotop --help
Usage: /usr/local/sbin/iotop [OPTIONS]
 
DISK READ and DISK WRITE are the block I/O bandwidth used during the sampling
period. SWAPIN and IO are the percentages of time the thread spent respectively
while swapping in and waiting on I/O more generally. PRIO is the I/O priority at
which the thread is running (set using the ionice command).
 
Controls: left and right arrows to change the sorting column, r to invert the
sorting order, o to toggle the --only option, p to toggle the --processes
option, a to toggle the --accumulated option, i to change I/O priority, q to
quit, any other key to force a refresh.
 
Options:
  --version             show program's version number and exit
  -h, --help            show this help message and exit
  -o, --only            only show processes or threads actually doing I/O
  -b, --batch           non-interactive mode
  -n NUM, --iter=NUM    number of iterations before ending [infinite]
  -d SEC, --delay=SEC   delay between iterations [1 second]
  -p PID, --pid=PID     processes/threads to monitor [all]
  -u USER, --user=USER  users to monitor [all]
  -P, --processes       only show processes, not all threads
  -a, --accumulated     show accumulated I/O instead of bandwidth
  -k, --kilobytes       use kilobytes instead of a human friendly unit
  -t, --time            add a timestamp on each line (implies --batch)
  -q, --quiet           suppress some lines of header (implies --batch)

 

 

参数

长参数

参数描述

 

--version

显示版本号

-h

--help

显示帮助信息

-o

--only

只显示正在产生I/O的进程或线程,运行过程中,可以通过按o随时切换

-b

--batch

非交互模式下运行,一般用来记录日志。

-n NUM

--iter=NUM

设置监控(显示)NUM次,主要用于非交互模式。默认无限

-d SEC

--delay=SEC

设置显示的间隔秒数,支持非整数

-p PID

--pid=PID

只显示指定进程(PID)的信息

-u USER

--user=USER

显示指定的用户的进程的信息

-P

--processes

只显示进程,不显示所有线程

-a

--accumulated

累积的I/O,显示从iotop启动后每个进程累积的I/O总数,便于诊断问题

-k

--kilobytes

显示使用KB单位

-t

--time

非交互模式下,加上时间戳。

-q

--quiet

只在第一次监测时显示列名. 去除头部一些行:这个参数可以设置最多3次来移除头部行:-q列头部只在最初交互显示一次;-qq列头部不显示;-qqq,I/O的总结不显示

 

  

iotop的快捷键

 

r:反向排序,

o:切换至选项--only,

p:切换至--processes选项,

a:切换至--accumulated选项

q:退出 

i:改变线程的优先级

 

 

iotop的例子

 

 

1:只显示正在产生I/O的进程

# iotop -o

 

 

2:使用非交互模式将iotop命令输出信息写入日志

#nohup iotop -b -o -n 10 -d 5 -t  > /tmp/iotop.log &

 

3:借助iotop命令找到消耗I/O最高的进程,然后通过进程找到其正在执行的SQL语句

 

# iotop -oP

 PID  PRIO  USER     DISK READ  DISK WRITE  SWAPIN     IO>    COMMAND                                                                                                                     

11741 be/4 oracle      4.70 M/s    0.00 B/s  0.00 % 98.60 % ora_s004_SCM2

11739 be/4 oracle     66.99 M/s    0.00 B/s  0.00 % 93.30 % ora_s005_SCM2

11741 be/4 oracle     21.76 M/s    0.00 B/s  0.00 % 91.78 % ora_s006_SCM2

11743 be/4 oracle      4.87 M/s    3.78 M/s  0.00 % 27.74 % ora_s007_SCM2

11745 be/4 oracle     62.39 K/s    0.00 B/s  0.00 %  2.88 % ora_s008_SCM2

11733 be/4 oracle     39.00 K/s    0.00 B/s  0.00 %  2.08 % ora_s002_SCM2                

11697 be/4 oracle      0.00 B/s 1879.61 K/s  0.00 %  0.30 % ora_dbw0_SCM2

11699 be/4 oracle      0.00 B/s  102.36 K/s  0.00 %  0.20 % ora_lgwr_SCM2

 

在找到消耗I/O最大的进程后,找出ORACLE进程正在执行的SQL语句

 

SQL> @getsql_by_spid.sql

Enter value for pid: 11741

old  13:                                WHERE c.spid = '&pid'))

new  13:                                WHERE c.spid = '11741'))

 

SQL_TEXT

--------------------------------------------

...............................(实际环境中,这里会输出SQL语句)

 

getsql_by_spid.sql脚本如下所示:

 

SELECT   /*+ ORDERED */
         sql_text
    FROM v$sqltext a
   WHERE (a.hash_value, a.address) IN (
            SELECT DECODE (sql_hash_value,
                           0, prev_hash_value,
                           sql_hash_value
                          ),
                   DECODE (sql_hash_value, 0, prev_sql_addr, sql_address)
              FROM v$session b
             WHERE b.paddr = (SELECT addr
                                FROM v$process c
                               WHERE c.spid = '&pid'))
ORDER BY piece ASC
/

 

这里只简单列了几个例子,因为iotop命令非常简单,了解iotop的参数和快捷方式后,基本上只需根据实际需求去获取进程或信息的I/O信息,剩下就是分析判断了。

计算机