> If you put a 5 second sleep in that loop, I expect you would see changes.
The exact number of seconds depends on /proc/sys/vm/dirty_*_centisecs value and /proc/sys/vm/laptop_mode...
Anyway, are you talking about file content or file name being written to disk in 5 seconds? Or both?
We can check whether content of deleted file is written to disk, run:
for i in `seq 100`; do dd if=/dev/zero of=f bs=1M count=10; rm -f f; done
then check /proc/diskstats or `iostat -k`. If you see writes increased in 1GB, your filesystem writes data even for deleted files. My ext3 does not.
> I do - once I found a suitably quiet ext3 filesystem to test on.
Try /boot. :) Or just insert some USB flash stick and create ext3 there.