Re: using rman

Holger Baer wrote:

Hi Holger,

> You don't need a second db, rman can track everything in the target
> databases controlfile - but only for a limited time. And besides, the OP
You consider this acceptable? All right, I never really worked with rman, and as I said, I didn't state it a bad product. The things I caught in the course were not really encouraging and besides we were already using shell scripts for online backups.
But returning, you consider storing rman info into the target database's controfile acceptable? When you have to restore an hot backup-ed db you have to recreate controlfiles, AFAIK, so where do you get restore info from?
And, what does "for a short time" mean? How far can you go back in time for a restore with rman this way?

> said he wanted to use rman, but not for how many databases it will be
Right.

> tape directly if that's needed. Considering todays hd prices you better
> throw in an additional disk just for the backups and use it as primary
> backup target (which will speed up backup as well).
I suppose, you did not really mean it litteraly, _one_ disk, what do you do with db with 200, 500, 1000 GB? One disk? What about CEO that just does not accept the "one disk more"?

> The shell script you propose will be much more complex and take much
> more time to develop - putting tablespaces in and out off backup mode,
Putting tablespaces in/out of backup mode is not really the issue, is it??? That's just three lines of code ...

> making sure you don't miss a datafile and so on. IMHO: that's an effort
You cannot miss a datafile if you ask the db which datafiles it holds, right?

What about time of backup and unavailability of backup destination? How does rman handle a situation where backup destination is not available (server down, tape unit broken, no tape space left)? How do you add the rest of the db to backup after you (admin) have fixed things next morning?

> not really necessary.

IMHO, yes. If you want call it effort. And we are talking about roughly 700 lines of shell script.
I, we, made the experience, that with the shell script we know what happens, as you have to ask the db for some info for what to backup, you get to know db details better. I have learned a lot with this method. We can backup parts of tablespaces a later moment (see unavailability issues above). I don't know with rman, but with my shell script I would be able to get things together for a complete restore manually also.

And finally, but maybe things changed or are not as I have understood and read white papers, using rman and having to store centrally on a Storage Manager you have to buy additional integration software (between rman and Storage Manager), which is $$ our CEO is not willing to spend.

>> Consider ...
> Exactly :-)

Exactly.

Have a nice day and thanks for your comments, Best regards,
Igor Received on Tue Jan 07 2003 - 09:35:15 CST