Comment 268 for bug 620074

André did you mean to take ownership of this bug away from Jens?

It looks like the test case I posted up earlier seems to be very effective at demonstrating at least one of the issues that is affecting people in this thread (namely people using ext3 or reiserfs).

It appears that xfs and ext4 are better at avoiding these huge latencies - I'm also assuming that the IO scheduler interacts with these filesystems differently.

Matt - I don't think this test case works for you as much because you have such a fast disk array. I imagine that you can write 10GB pretty quickly with an 8-drive array. Try increasing the 10GB to 100GB and increasing the sleep to 20-30 seconds so that you get more data waiting to be flushed to disk.