Comment 28 for bug 204133

Just to add, if one needs to check how effective the sysctl's are, I suggest the following:

watch -n 1 grep -A 1 dirty /proc/vmstat

also if one wants to see which blocks are being flushed and by which process one can do:

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

and looking at the output from dmesg will show that the data is being flushed out.

There still seems to be a bit of delay in fully flushing blocks out with the suggested sysctl's. I've fiddled with various settings but I could not seem to improve things.