Re: Informix backup/archives

} Is it a true statement that I will never need any logical log tapes } that were written *before* my last level 0 archive? In other words, } when I do a level 0 archive, I am getting essentially a snapshot of } my database right then, so any logical log tapes made *before* then } are no longer needed. Correct??? Correct - in a perfect world. What if the tape with the latest level 0 archive turns out to be bad, or gets destroyed in a fire, or any of a hundred other possibilities? If you have all the previous level 0, plus all log files since then, you can restore and roll forward. It will take a long time, but it would save you from the bad tape. } It looks as if the "ontape -c" logical log backup process and the } "ontape -s -L 0" archive process are completely unaware and completely } independent of each other. When I stop my ontape -c process and let } a few logical logs build up on disk not backed up, and then I do a } level 0 archive, then those logical logs that are sitting there not } backed up are not really needed anymore (I think). But yet those same } logical logs will not get reused until I back them up. Why do I have } to back them up if I don't need them anymore??? Shouldn't the level 0 } archive somehow flag those logical logs as no longer being relevant, } so that the space can get reused?? Informix probably doesn't flag the logical logs so that you can still back them up in case of the scenario I described above. } If I do a restore from the same level 0 archive mentioned in the last } paragraph (without restarting ontape -c), will ontape be smart enough } to roll forward the logical logs stored on disk that haven't been } backed up yet? Or will it only roll forward from tape??? Online will give you the opportunity to back up the logical logs at the beginning of the restore. I believe (and expect to be corrected if I'm wrong) that if you want to roll forward, you have to back up these log files, because during the restore the reserved pages in rootdbs would be restored as well, which would effectively erase any record of the logical logs after the level 0. Mark Collins mcollins@us.dhl.com The problem lies in how easily and dangerously we forget that manipulating things is not the same as understanding them.