Pando,

I really can't reply to the use of Omniback, I was at a shop for a short time where they used it to backup their server. But it was a small shop and they could be assured of very low usage at night, so they would set the entire database into backup mode and backup it entirely at one time. It was also a rather small database so it wasn't a real problem.

In my shop I have set up my production servers using RAID 1 + 0 and created a third mirror for my backup. At night I resilver the third mirror, set all tablespaces into backup mode and break the mirror, then take all tablespaces out of backup mode. This process to break the mirror and take all tablespaces out of backup mode for eight databases takes less then one minute, so I don't have to worry about redo logs. Then I can backup the mirror to tape at my leasure. I do this because DLT tapes are not fast. There are some newer ones coming out later this year that have a faster speed, but DLT technology is not new and it is not very fast.

Sorry I couldn't answer you question directly, but hope this helps some.