If you have SuSE, you are lucky - SuSE is the first distro I have found
that allows you to overcome this problem. The blinking disk light is
caused by the kernel flushing cache pages to disk - I won't pretend to
understand the full in and out of it, but basically, after a process
writes anything to a variable, the memory page holding it is marked as
"dirty". The kernel flushes "dirty" pages to disk every 5 seconds by
default, so that in the event of a crash, you don't lose more than 5
seconds of data.
SuSE 9.3 at least (not sure if 9.2 does this - I have 9.0 and 9.3) lets
you change the default time between wakeups of the "dirty page flusher"
process. Go to YaST, System, Powertweak Configuration, Virtual Memory,
bdflush - change the value of dirty_writeback_centisecs from its
default of 500 (= 5 seconds) to some value you find acceptable. It is a
tradeoff between how much data you are willing to lose in a crash and
how annoying you find the disk flashing. I have set mine to 3000 (= 30
s). Works like a charm.