LINUX下查找最耗IOWAIT的进程(转)

抓哪个进程干坏事前要先停掉syslog
service syslog stop

打开block dump:
echo 1 > /proc/sys/vm/block_dump

统计：
dmesg | egrep "READ|WRITE|dirtied" | egrep -o '([a-zA-Z]*)' | sort | uniq -c | sort -rn | head
1423 kjournald
1075 pdflush
209 indexer
3 cronolog
1 rnald
1 mysqld
Linux命令dmesg用来显示开机信息，kernel会将开机信息存储在ring buffer中。您若是开机时来不及查看信息，可利用dmesg来查看。开机信息亦保存在/var/log目录中，名称为dmesg的文件里
不要忘记在抓完之 后关掉block_dump和启动syslog:
echo 0 > /proc/sys/vm/block_dump
service syslog start


加个有人写了一个perl脚本来处理输出，能得到更直观的结果：

参考：http://www.xaprb.com/blog/2009/08/23/how-to-find-per-process-io-statistics-on-linux/

wget http://aspersa.googlecode.com/svn/trunk/iodump

echo 1 > /proc/sys/vm/block_dump

while true; do sleep 1; dmesg -c; done | perl iodump

root@kanga:~# while true; do sleep 1; dmesg -c; done | perl iodump
^C# Caught SIGINT.
TASK PID TOTAL READ WRITE DIRTY DEVICES
firefox 4450 4538 251 4287 0 sda4, sda3
kjournald 2100 551 0 551 0 sda4
firefox 28452 185 185 0 0 sda4
kjournald 782 59 0 59 0 sda3
pdflush 31 30 0 30 0 sda4, sda3
syslogd 2485 2 0 2 0 sda3
firefox 28414 2 2 0 0 sda4, sda3
firefox 28413 1 1 0 0 sda4
firefox 28410 1 1 0 0 sda4
firefox 28307 1 1 0 0 sda4
firefox 28451 1 1 0 0 sda4