http://www.jackxiang.com/index.php zh-cn http://www.jackxiang.com/post// jack <xdy108@126.com> Sun, 29 Dec 2013 12:35:57 +0000 http://www.jackxiang.com/post//

环境： Ubuntu
1. 开启IO监控
sudo sysctl vm.block_dump=1
2. IO监控开启后，系统将记录程序对所有硬盘块的访问，通过dmesg查看
dmesg
[442825.284270] mysqld(11600): READ block 6676888 on xvdb2 (8 sectors)
[442825.289893] mysqld(11600): READ block 11543240 on xvdb2 (8 sectors)
[442825.291317] mysqld(11600): READ block 11543248 on xvdb2 (24 sectors)
3. 使用awk汇总，得到占用磁盘最多的进程
dmesg |awk -F " " '{print $2}'|sort|uniq -c|sort -rn|head -n 100
1564 mysqld(11600):
994 python(11474):
302 nginx(6171):
136 mysqld(29743):
126 mysqld(15528):
71 ntpd(772):
62 mysqld(16837):
4. 调试完毕后，别忘了关闭IO监控。
sudo sysctl vm.block_dump=1

摘自：http://www.luochunhui.com/linux-io-dmesg/
参考：http://blog.slogra.com/post-317.html
实践：
[root@my htdocs]# vi /proc/sys/vm/block_dump
[root@my htdocs]# sysctl vm.block_dump=1
vm.block_dump = 1
[root@my htdocs]# dmesg |awk -F: '{print $1}'|sort|uniq -c|sort -rn|head -n 10
    195 ACPI
    194 pci 0000
     63   alloc kstat_irqs on node 0
     53 pnp 00
     48 ioatdma 0000
     34 igb 0000
     34 EDAC sbridge
     29 flush-253
     26 SRAT
     24 pci_bus 0000
[root@my htdocs]# sysctl vm.block_dump=0    
vm.block_dump = 0 ]]> http://www.jackxiang.com/post//#blogcomment <user@domain.com> Thu, 01 Jan 1970 00:00:00 +0000 http://www.jackxiang.com/post//#blogcomment