If you're running Oracle, that company is notorious for wanting things done a certain way. I'd go to their site and see what I could dig up. Never tried to back those up manually, but if you can take it offline for read time, I would think you could do a raw bit copy with dd.
What version of RHEL being used? Is the file system sitting on top of an LV? If so, you can easily make a backup solution with LVM snapshot and rsync. This should let you take back up regularly.
Post the details I need and I may help you with scripting the things.
Thanks for the replies. I actually scp'ed the files to another off-site location as a temporary measure until I get an RMAN full backup in place.
R,
D.