Re: disaster recovery

From: joel garry <joel-garry_at_home.com>
Date: Mon, 19 May 2008 11:18:36 -0700 (PDT)
Message-ID: <4b935248-c3db-4a5d-a2ac-08690425dc17@b5g2000pri.googlegroups.com>


On May 16, 12:52 am, Frank van Bortel <frank.van.bor..._at_gmail.com> wrote:
> Ben wrote:
> > On May 15, 2:31 pm, joel garry <joel-ga..._at_home.com> wrote:
> >> On May 15, 10:14 am, Ben <benal..._at_yahoo.com> wrote:
>
> >>> 10.2.0.2 EE aix5l 64bit
> >>> I guess I'll just reference my post that was somehow moved.
> >>>http://tinyurl.com/5zej6a
> >>> I was wondering about the statement of better to use a current
> >>> controlfile rather than one that I recovered. Why is it better?
> >>> I believe I'm going to have to do a pitr, so why not just use the
> >>> controlfile and spfile that was included in the hotbackup that I'm
> >>> going to be using for recovery?
> >> I think it's just easier to let Oracle do if possible, but if you are
> >> PITR then do what you need to.  As always, it depends.  A lot of calls
> >> for help here indicate people are unclear on when to use which syntax
> >> (like using backup controlfile and such), often they will make it more
> >> complicated than necessary and blow it.  The trick is to understand
> >> how Oracle compares SCN's in datafile headers and controlfiles, in
> >> order to decide what recovery is needed.  The bit about disk versus
> >> tape - if you still have an original controlfile on disk and the
> >> archived logs that the recovered data files will need, you probably
> >> want to use that one, letting Oracle recover as much as it can, and
> >> rollback the rest.  But it depends on why you want PITR - what
> >> happened that you don't want to be committed?  If it is just all your
> >> disks got wiped including archived logs and you need to restore to the
> >> past, just do that.
>
> >> jg
> >> --
> >> @home.com is bogus.
> >> Maybe it's just customers who are stable enough to use remote DBA
> >> support that are slow to adopt...http://www.computerworlduk.com/technology/business-intelligence/datab...
>
> > The reference to disk in the original post was a typo, the only disk
> > that the server can still find data on, is the root system disk. We
> > may be able to get back the filesystem that included the oracle home.
> > If we can, that would include our spfile and alert log from the day
> > before the outage. Other than that, I don't have anything left except
> > for backup pieces on tape.
>
> > The specific timeline of events was
> > Friday. full hot backup
> > Sunday: power outtage to disk cabinet, server's conception of disks
> > are scrambled.
> > Monday: we realize that the server is up but no data.
>
> I have to disagree with Joel on this one - *always* use the most
> current controlfile - it has the most up-to-date state of
> your database. OK - having said that:
> Just restore your backups on a (different) machine.
> Mount, alter the locations of the tablespaces, move
> the datafiles around, recover (maybe until cancel, or
> until sunday/seconds before crash) and open.
>
> Sounds so simple, and sometimes it is.
>
> May the force be with you.
>
> FvB

See step 3 at http://download.oracle.com/docs/cd/B19306_01/backup.102/b14191/rcmtspit001.htm#i1008453

Hey, if RMAN does it... but I'm still not clear why a PITR would be desired here anyways.

As far as simplicity, well, sometimes this stuff has too much abstraction between what is going on and the very high level RMAN commands, that can be very confusing.

To Ben: Frank is better at this stuff than me, Sybrand certainly is.

jg

--
@home.com is bogus.
Thought I could skip the Playstation 2 generation and go right to the
newer ones, until someone wanted Dance Dance Revolution for Mother's
day.  One version for 3, one version for X-box, one version for Wii,
lots for P2.  It _is_ the app.<sigh>
Received on Mon May 19 2008 - 13:18:36 CDT

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