From http://balajitheone.blogspot.com
IO wait load tracking to a process.
How to identify what processes are generating I/O wait load.
————————————————————-
An easy way to identify what process is generating your IO Wait load is to enable block I/O debugging. This is done by setting /proc/sys/vm/block_dump to a non zero value like:
echo 1 > /proc/sys/vm/block_dump
This will cause messages like the following to start appearing in dmesg:
bash(6856): dirtied inode 19446664 (ld-2.5.so) on md1
Using the following one-liner will produce a summary output of the dmesg entries:
dmesg | egrep "READ|WRITE|dirtied" | egrep -o '([a-zA-Z]*)' | sort | uniq -c | sort -rn | head
354 md
324 export
288 kjournald
53 irqbalance
45 pdflush
14 portmap
14 bash
10 egrep
10 crond
8 ncftpput
Once you are finished you should disable block I/O debugging by setting /proc/sys/vm/block_dump to a zero value like:
echo 0 > /proc/sys/vm/block_dump
Nice…
