Saturday, July 26, 2008

block I/O debugging in Linux

block_dump option enables you to see all read/write and block dirtying operations on files. It's default value is 0. Setting value to 1 enables block I/O debugging.


echo "1" > /proc/sys/vm/block_dump

You can see the log via dmesg, here is a sample output.



to set if off:

echo "0" > /proc/sys/vm/block_dump