In recent kernel (2.4.20pre...), an option (commit) is available.
have crashes only when experimenting with the kernel, I think this is
not as bad as it might look at first glance. But, you know, no
guarantees of mine, your filesystem might become garbled, your hard
disk might become fried!
In my opinion this is not a solution. First I am still not convinced
that it is normal for ext3 to touch the disk when there is no other
activity on the system. Then spinning the disk for 5 minutes seems very
bad from the powersaving point of view and also from the life of the HD.
That said if you have done nothing else, I am not sure if your disk
enter in a powersaving state. Have you tweaked it with hdparm or are you
using noflushd?