Restore of Oracle database from DP tape copy

[MAUME Nicolas]

Hello,

I'm not able to recover an Oracle database using Dataprotector from a media copy.

The configuration is :
Server : Windows / Windows 2003 Enterprise R2
Database : Oracle 9i

The 03-13-2009, a backup full of the database has been done on a media. This original media has been copied on another media.
The original media has been erased since this date. But now, when we are trying to restore the database, we encounter following message :
"no backup or copy of datafile x found to restore"

It seems that Rman is not able to see the media copy, and try to find the original media.

Have you ever experiencing such issue ? Is there a solution ?

I attach to this thread the Dataprotector session log.

Thanks in advance for your answer,
Nicolas.

[emha]

Hi,

which way have you made copy of original tape?
rman probably is not aware of it.

you may list what backups is rman aware of by
list backup recoverable until time "to_date('03/13/09 22:00:00','MM/DD/YY HH24:MI:SS')"


if you are able to address single backup sets/pieces on the copied tape you may rman let to know about it using 'backup ... backupset ...' command.
more details see here
http://download.oracle.com/docs/cd/B10501_01/server.920/a96565/toc.htm

emha.

[MAUME Nicolas]

Hi Emha,

Thank you for your answer.

My backup isn't available anymore for rman because the retention period is 55 days.
Here is the result of the "list" command :
List of Backup Sets
===================

BS Key Size Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ ---------------
687 2G SBT_TAPE 00:00:31 11-MAY-09
BP Key: 683 Status: AVAILABLE Tag: TAG20090511T210501
Piece Name: vcc-gnb-vmxd52-MXVCC-daily<686610302:1>.dbf

List of Archived Logs in backup set 687
Thrd Seq Low SCN Low Time Next SCN Next Time
---- ------- ---------- --------- ---------- ---------
1 1959 65543671 08-MAY-09 65656707 10-MAY-09
1 1960 65656707 10-MAY-09 65677858 10-MAY-09
1 1961 65677858 10-MAY-09 65680226 10-MAY-09
.....

Is it actually possible to restore my database from an unknown backup ?

Regards,
Nicolas.

[emha]

rman retention policy controls when backup may become OBSOLETE, not availability on backup media.

howevers DP may have configured its own retention policy for single backups that do not need to follow rman ones.

until you perform crosscheck/delete rman keeps record of all the backups regardless of their AVAILABILIY on backup media.

whether you will be able to recover your database from March's backup depends on whether you can identify backup sets on the copied tape and whether you will be able to catalogize them into rman.

emha.

[MAUME Nicolas]

Ok, thank you for these information.

As far as I understand, as my backup of March still exists, a solution would consist in cataloging the backupsets into the rman repository.
After analyze, it's seems to be impossible for backup type media. The solution is possible only for datafilecopy on disk.
So I tried to restore the datafiles on disk in a first time, but DP is not able to restore Oracle backupset because it doesn't see it on the filesystem restore session.

Have you got any idea ?
Thanks and Regards,
Nicolas.

[emha]

you still haven't mentioned which way you made tape copy. so I will asssume you used DP media copy functionality.

if so, according DP help, when rman requests to restore a backup piece, DP should recognize it and if the respective tape isn't available in media pool it should ask for correct tape with 'mount request;.


Restoring from a copy
By default, Data Protector restores data from the original media set. However, if the original media set is not available, but a copy is available, the copy is used for the restore.

If neither the original nor a copy is available in the device during restore, Data Protector issues a mount request, displaying both the original and the copy as the media required for restore. You can use any one of these.

If you perform a restore using a standalone device, you can choose to restore from the copy rather than from the original. To do this, insert the copy in the device that will be used for the restore, or select the device containing the copy. However, if you perform a restore using a library device and the original is in the library, Data Protector will use it for the restore.



however, I do not use this DP functionality so I do not know how does it in fact works in relation to DP retention policy and whether it will ask for backup tape once original tape has been expired.

emha.

[MAUME Nicolas]

Sorry, I don't know how the copy has been done. It was built by another person. But I think that the DP media copy functionality has been used.

The functionality you mentioned (restoring from a copy) is working find for filesystem backup. We have executed successfully a restore of the filesystems. As you explain, a mount request is asked. But it doesn't work for Oracle datafiles.

I attach to the thread copy screens of my Oracle restore session. You'll see that DP never asks for correct tape with 'mount request'.

Hope this can help.

Thanks and Regards,
Nicolas.

[emha]

RMAN-06026 means rman can not find a backup that would would satisfy your requirements, so it doesn't know what to request from DP and therefore no mount request from DP side.

one chance is that you still have obsolete records in your catalog and you somehow convince rman that these backups are not obsolete yet (directly overwrite status in rman catalog tables?)

if neither obsolete records of your backup exists, then I'm sorry, I do not know how you might recover your DB in this situation.



just an idea how it would be possible, but if it had worked it would have been just miracle...
if you can see your tape among medias in some DP pool, there is a chance to read out backup set and backup pieces ID-s. with these info you may try to manually insert necessary records directly into rman catalog tables (see their docu on http://download.oracle.com/docs/cd/B10501_01/server.920/a96565/toc.htm)


emha.

[MAUME Nicolas]

What is given to DP is the Barlist name (ENV params on the restore session). As I understand, DP links the Barlist to an ID depending on the "until time" clause of the restore session. I cannot reference directly the media name on the rman command, I can only catalog it on rman repository.

So as recommanded, I changed my backupset of March to available status. But it seems impossible to catalog the new backupset on rman.

Here are the Oracle limitations:
"You cannot use CATALOG to perform the following operations:
Recatalog backup pieces or backup sets. If you run CHANGE ... UNCATALOG against an RMAN backup, then it is permanently unusable by RMAN.
Rename a backup piece or move a backup piece from one place to another."

It seems there is no solution....
Many thanks for your help!
Nicolas.