read man hdparm
for the correct parameters to use.
WARNING: I am no expert at this and only use hdparm on my hard drives with no obvious speed boost. This may not fix your prob and may rodger things in a good and proper fashion. Read the texts first so you can decide on the safety of the procedure yourself.
from my reading this is what you need. you'll need to be root by typing su
and then the root password (this is all done at the command line)
hdparm -x34 d1 /dev/yourdvddrive
If that work ok then put it in your start up script rc.local. I don't use red hat so only know that this file is somewhere in /etc/rc.d/
to check it is working use the following commands before and then after the previous command (not sure whether this works with DVD drives [not sure any of this does] but you'll definately need a data cd in it of some description).
hdparm -tT /dev/DVDdevice
This will give you information about the throughput of the ide device.
That may work though that last command will need to be done several times to get an average (preferably with as few processes running as possible) of the speed of your drive interface.
On a side note, what may make things wizz a long at a better pace would be to make sure that your ide bus is nipping along at its fastest capable speed. ask if you need more help on how to do this (if not dfone already).
P.S. wow, 300 posts now......