Originally posted by julian
.. with raw devices RMAN has to know in advance the exact size of the backup.
This is not true.

(Do you backup raw files with RMAN?)
Ok, can you then explain why you can't perform hot backup with RMAN with raw volume *as a destination of the backup*?
Or for that matter (and this has nothing to do with RMAN, but the reason is the same), why you can't have raw device as the archive logs destination?

I'm not sure I understand your last question. Nobody said you can't backup raw files with RMAN. The whole isue in this thread is raw device as a *destination* of the backup!

I'm sure you know that with raw you have to specify the exact size of the file *at creation time*, in contrast with file system, where you can create file without specifying its size, start writing to it, apending new blocks to it until you are done, and thus creating a file of whatever size it needs to be to hold all information.

I never tried to made a hot backup to raw volume as a destination - I belive the Oracle documentation on this one and I use some plain logic to belive it can't be done! Have you been sucsessfull in persuading RMAN to write hot backup to raw device as the destination, perhaps???

[Edited by jmodic on 10-05-2001 at 06:00 PM]