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Question and Answer

Connor McDonald

Thanks for the question, Lucas .

Asked: November 13, 2025 - 6:49 am UTC

Last updated: November 18, 2025 - 2:44 am UTC

Version: 12.1

Viewed 100+ times

You Asked

Hi Tom, good morning

My question is very clear and generic, and very important for me due to a current discussión in my team:

We have a database in the followint situation, the worst scenario, I guess:

- standalone (no RAC, no Dataguard)

- Only one disk with all inside: data, flash_recovery_area (so archive logs), redo logs online and control files with not multiplexion (only one redo logs online member and only a control file copy) and the ORACLE_HOME

- My dadabase is in archivelog mode, taking weekly backuppieces with RMAN, BUT, there is NO RECOVERY CATALOG (usded control file instead) and AUTOBACKUP OF CONTROL FILE IS OFF -default

If there is a MEDIA FAILURE, so the disk is destroyed, although Veritas is making the backups, ¿Is there a way to recover the database in this situation after a complete disk failure? ¿could rman preveiw cuould help in any way?

I think, it is not possible, but "someone" at my team says yes. ¿am I wrong?

Thanks a lot for your time and your help

-Best regards

and Connor said...

A standard backup will contain a copy of the control file even if autobackup is not present, eg

RMAN> configure controlfile autobackup off;
configure controlfile autobackup off;
new RMAN configuration parameters:
CONFIGURE CONTROLFILE AUTOBACKUP OFF;
new RMAN configuration parameters are successfully stored


RMAN> list backup;
list backup;
specification does not match any backup in the repository


RMAN> backup database;
backup database;
Starting backup at 18-NOV-25
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=372 device type=DISK
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
input datafile file number=00002 name=X:\ORACLE\ORADATA\DB19S\SOE.DBF
input datafile file number=00001 name=X:\ORACLE\ORADATA\DB19S\SYSTEM01.DBF
input datafile file number=00003 name=X:\ORACLE\ORADATA\DB19S\SYSAUX01.DBF
input datafile file number=00005 name=X:\ORACLE\ORADATA\DB19S\LARGETS.DBF
input datafile file number=00007 name=X:\ORACLE\ORADATA\DB19S\USERS01.DBF
input datafile file number=00004 name=X:\ORACLE\ORADATA\DB19S\UNDOTBS01.DBF
channel ORA_DISK_1: starting piece 1 at 18-NOV-25
channel ORA_DISK_1: finished piece 1 at 18-NOV-25
piece handle=X:\ORACLE\BKP\DB19S\0A49344G_1_1 tag=TAG20251118T101440 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:07
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
including current control file in backup set <<<==========
including current SPFILE in backup set
channel ORA_DISK_1: starting piece 1 at 18-NOV-25
channel ORA_DISK_1: finished piece 1 at 18-NOV-25
piece handle=X:\ORACLE\BKP\DB19S\0B49344N_1_1 tag=TAG20251118T101440 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 18-NOV-25


RMAN> list backup;
list backup;

List of Backup Sets
===================


BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
5       Full    8.16G      DISK        00:00:05     18-NOV-25
        BP Key: 5   Status: AVAILABLE  Compressed: NO  Tag: TAG20251118T101440
        Piece Name: X:\ORACLE\BKP\DB19S\0A49344G_1_1
  List of Datafiles in backup set 5
  File LV Type Ckp SCN    Ckp Time  Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- --------- ----------- ------ ----
  1       Full 16331251381522 18-NOV-25              NO    X:\ORACLE\ORADATA\DB19S\SYSTEM01.DBF
  2       Full 16331251381522 18-NOV-25              NO    X:\ORACLE\ORADATA\DB19S\SOE.DBF
  3       Full 16331251381522 18-NOV-25              NO    X:\ORACLE\ORADATA\DB19S\SYSAUX01.DBF
  4       Full 16331251381522 18-NOV-25              NO    X:\ORACLE\ORADATA\DB19S\UNDOTBS01.DBF
  5       Full 16331251381522 18-NOV-25              NO    X:\ORACLE\ORADATA\DB19S\LARGETS.DBF
  7       Full 16331251381522 18-NOV-25              NO    X:\ORACLE\ORADATA\DB19S\USERS01.DBF

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ ---------------
6       Full    10.52M     DISK        00:00:01     18-NOV-25
        BP Key: 6   Status: AVAILABLE  Compressed: NO  Tag: TAG20251118T101440
        Piece Name: X:\ORACLE\BKP\DB19S\0B49344N_1_1
  SPFILE Included: Modification time: 18-NOV-25
  SPFILE db_unique_name: DB19S
  Control File Included: Ckp SCN: 16331251381526   Ckp time: 18-NOV-25       <<<==========


RMAN>


Thus if you had a full backup restored from Veritas, you could

- restore the control file from the backup
- use that to restore the database and the archivelogs
- recover the database *incompletely* because your online redo logs are gone.

So its possible...but as you've already noted, your setup is definitely not ideal

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Comments

another special situation added

Lu, November 18, 2025 - 8:16 am UTC

Thanks a lot for your fast and clear response.

But i have another concern. What happen if, something in the scructure of the database have changed after the last backup, for example, you have added some datafiles and you have deleted another ones, or you have create new tablespaces and deleted another ones. Or something simililar. In this situation, ok, you have all the archiveogs, but are this changes resgisterd too? the control file previously backed up don't have the current "inventary" of the physical situation, do it?. I imagine, that you should customize an script to recreate the control file taking this changes from the alert log? -but, remember that alert log whas losted, becasue all were in the same disk, incluidng ORACLE_HOME and /diag

Thanks a lot in advance
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