I back up with RMAN my raw partitions to TAPE. I have hot-backed up with DD my raw-partitions too. Here is the biggest problem you might face when you use raw devices. With OPS, you have to (almost always) use raw files. However, Oracle requests that archivelogs are cooked. Imagine Modic, if you have to make with Volume Manager a raw partition for every archive log :-) You cannot often control their amount. If your redologs are say 10M, how many raw partitions of 11M (why 11 :-)) do you have to make? The Oracle solution is cooked files for archive logs. The answer to your first question is clear to you now, probably. So, is the second answer, I believe. The 3rd one: NO :-)