Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Mailing Lists -> Oracle-L -> Re: backup of offline dropped datafile

Re: backup of offline dropped datafile

From: Mindaugas Navickas <mnavickas_at_yahoo.com>
Date: 2005-12-23 20:19:58
Message-id: 20051223191958.45796.qmail@web30114.mail.mud.yahoo.com


Hi,

In fact Koen is right raising concern about backup/recovery - here is a test I did - tablespace USERS had two datafiles that were offline droped. The test was done on Oracle 10.2.

Probably the best option in this situation would be recreating tablespace.



Starting backup at 23-DEC-05
using target database control file instead of recovery catalog allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=23 devtype=DISK
could not read file header for datafile 5 error reason 1
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of backup command at 12/23/2005 14:03:34 RMAN-06056: could not access datafile 5

RMAN> backup database skip inaccessible;

Starting backup at 23-DEC-05
using channel ORA_DISK_1
could not access datafile 5
skipping inaccessible file 5
could not access datafile 6
skipping inaccessible file 6
RMAN-06060: WARNING: skipping datafile compromises tablespace USERS recoverabili
ty
RMAN-06060: WARNING: skipping datafile compromises tablespace USERS recoverabili
ty
channel ORA_DISK_1: starting full datafile backupset channel ORA_DISK_1: specifying datafile(s) in backupset

input datafile fno=00001 name=C:\ORACLE\DATA\SYSTEM01.DBF
input datafile fno=00004 name=C:\ORACLE\DATA\USERS01.DBF
input datafile fno=00002 name=C:\ORACLE\DATA\UNDOTBS01.DBF
input datafile fno=00003 name=C:\ORACLE\DATA\SYSAUX01.DBF
channel ORA_DISK_1: starting piece 1 at 23-DEC-05 channel ORA_DISK_1: finished piece 1 at 23-DEC-05 piece
handle=C:\ORACLE\FLASH_RECOVERY_AREA\MN\BACKUPSET\2005_12_23\O1_MF_NNNDF_T AG20051223T140941_1TRLVP81_.BKP tag=TAG20051223T140941 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:01:25
channel ORA_DISK_1: starting full datafile backupset
channel ORA_DISK_1: specifying datafile(s) in backupset
including current control file in backupset channel ORA_DISK_1: starting piece 1 at 23-DEC-05 channel ORA_DISK_1: finished piece 1 at 23-DEC-05 piece
handle=C:\ORACLE\FLASH_RECOVERY_AREA\MN\BACKUPSET\2005_12_23\O1_MF_NCNNF_T AG20051223T140941_1TRLYDB3_.BKP tag=TAG20051223T140941 comment=NONE channel ORA_DISK_1: backup set complete, elapsed time: 00:00:02 Finished backup at 23-DEC-05
RMAN>

Regards
Mindaugas Navickas
OCP

> Tanel, Koen
>
> I do not think that Oracle would ever request a space from a datafile that is
> offline.
> From the scenario that Koen described, it doesn't look that storage been
> allocated for any objects in the dropped data file, so queries against
> objects
> shoudn't fail.
> Even if you recreate controlfiles/resetlogs (from backup or from trace),
> offline datafile will still apear in v$datafile - there is nothing you can do
> about it - but from my understanding it should not cause any issue.
>
> Regards
> Mindaugas Navickas
> OCP
> --- Tanel Põder wrote:
>
> > Hi,
> >
> > If your queries fail because of unaccessible data in this datafile then
> > there's not much you can do.
> >
> > If you add another datafile then you might get errors when segments need to
>
> > extend (into the offline datafile), this could be worked around by
> > preallocating extents for your segments. (it might not be enough when
> you're
> > doing direct path inserts though).
> >
> > From recovery part I don't see any other problems than additional
> complexity
> > and running with a tablespace in an abnormal state. I wouldn't personally
> > like to run my production database in such mode at all.
> >
> > Tanel.
> >
> > ----- Original Message -----
> > From: "Koen Van Langenhove"
> > To:
> > Sent: Friday, December 23, 2005 9:38 AM
> > Subject: backup of offline dropped datafile
> >
> >
> > > Hi,
> > > First things first:
> > > - 9.2.0.4 2-node RAC
> > > - solaris 8 / sun cluster 3.0
> > > - VxVM 3.2
> > > - production system, rather urgent
> > >
> > > we have this little situation where someone dropped a datafile using
> > > 'offline drop'. This was apparently not the best solution for its problem
>
> > > and we don't have archivelogs available to recover the datafile (only the
>
> > > archivelogs created during the backup are kept .. don't ask ..).
> > >
> > > As I understand it right now, there's no way we can "undrop" this
> > > datafile, our only option is to drop the tablespace and recreate it,
> which
> > > is what we'll do eventually. To get out of this situation we would like
> to
> > > continue for a while with this datafile dropped, while adding another
> > > datafile to make up for the lost space.
> > >
> > > Now, the question is, is this a good idea ? My main concern is
> > > backup/recovery, but any other hints would be highly appreciated.
> > >
> > > TIA,
> > > Koen
> > >
> > > PS the original problem:
> > > - added a datafile
> > > - the second node didn't have its symlink to the new vxvm volume
> > > - adding the datafile worked, everything fine on node 1
> > > - on node 2, got ORA-01157 on the new datafile
> > > - created symlink but the instance did not pick up the datafile
> > > - offline drop the datafile to bring the db into service again (while a
> > > 'alter system check datafiles' would have fixed it)
> > >
> > > --
> > > Regards,
> > > Koen
> > >
> > > Siemens COM
> > > COM D MN A
> > >
> > > Email : Koen.Van_Langenhove_at_siemens.com
> > > - - - - - - - Unix IS user-friendly .., it's just quite picky about its
> > > friends.
> > >
> > > --
> > > http://www.freelists.org/webpage/oracle-l
> > >
> > >
> >
> > --
> > http://www.freelists.org/webpage/oracle-l
> >
> >
> >
>
>
>
>
>
>
>
> __________________________________________________________
> Find your next car at http://autos.yahoo.ca
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>
                                  



Find your next car at http://autos.yahoo.ca
--
http://www.freelists.org/webpage/oracle-l
Received on Fri Dec 23 2005 - 20:19:58 CST

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US