Re: Backup opinions

On Wed, Aug 13, 2008 at 3:43 PM, Nuno Souto <dbvision_at_iinet.net.au> wrote:

>
>
> DUPLICATE TARGET works for refreshing a database.
>> I have at times had issues getting this to work however.
>> That was on NBU 5.x, and were are now on 6.0 MP5.
>> I did a DUPLICATE TARGET a couple weeks ago without issue.
>>
>
>
> What happens if you have to re-destribute file
> locations during the DUPLICATE TARGET.
> For example: not the same file systems in
> the AUXILIARY, have to move files to other?
>

I use the db_file_name_convert log_file_name_convert parameters in the init.ora. My method is to query v$datafile and v$logfile, along with

other file v$ views, to generate the initi.ora parameters, generate mkdir commands and whatever else is needed when the destination of the new files does not match the source. mkdir probably isn't needed, RMAN will likely do that, but it's just an old habit at this point.

>
> IOW: is the full flexibility of the DUPLICATE command
> and extra settings with an FRA still available?
>

Don't know. If using Veritas NBU, the files have to somehow be transferred from the backup to the auxiliary server. If the backup is on tape, NBU just does an 'alternate client' restore via RMAN.

If the backup is in the FRA, how will NBU access the backup? How will it transfer the restored files to the auxiliary server? I'm guessing it can't, though I'm willing to be surprised.

>
>
> And are redo logs also being archived directly to
> tape?
>

Yes they are. Using FRA for archive logs only is something I have considered doing, just need to experiment with it and learn the 'gotchas'.

>
>
> How does Netbackup then operate in a recovery
>> situation?
>> Quite an open ended question, anything specific you are looking for?
>>
>
>
> Lost system, need to recover to DR site with different
> file system configuration.
> How does the interaction between control files,
> data and archived redo log files happen from
> tape? Is it possible to PITR without any hassles?
>

If you have a recovery catalog to work with, you would set DBID=<DBID> in RMAN, recover the control files and spfile, then proceed with the recovery.

If you have lost everything, and don't have a recovery catalog, life will be more difficult.

You will need to set ORACLE_SID and DBID as per normal, and then do a 'restore controlfile from autobackup'. There are some parameters that can be used to limit the searches on the backup database, lest this restore take many hours. (MAXSEQDAYS is one of the parameters IIRC). You would also want to restore the spfile.

Then it is a matter of 'recover database', mount and open.

You have hopefully been creating 'autobackup' controlfiles.

If not, you have to do something else. I have not practiced this scenario, so at this point I would have to go to the docs and figure it out. Probably something I should learn to do.

-- 
Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist

--
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