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Re: redo log corrupted

 
Hunan_1
Frequent Advisor

redo log corrupted

I have a redo log corrupted, How can I start to solve the problem.

any help would be really appreciated,
17 REPLIES 17
Pete Randall
Outstanding Contributor

Re: redo log corrupted

What do you mean by a "redo log"?

Pete

Pete
Ian Lochray
Respected Contributor

Re: redo log corrupted

I presume you are talking about an Oracle redo log. If so, how did the corruption manifest itself and what error message(s) did Oracle report?
Hunan_1
Frequent Advisor

Re: redo log corrupted

yes, I'm talking about oracle redo log,
I have 4 groups mirrored everyone of them in different disks.

At certain moment, the oracle's log shows that there was an inconsistency in one redo log.

Then, I shutdown the database, after when it was been restarted with the resetlogs option, the following message was shown.

alter database open resetlog
*
ORA-01194: El fichero 1 necesita mas recuperacion para ser consistente.
ORA-01110: Fichero de datos 1 :"/opt/oracle8/...."

It's not matter if I lost the data, I would be really pleased if someone could help me to put it working again.

Thanks

Stan_17
Valued Contributor

Re: redo log corrupted

Hunan,

presuming you lost the current redolog, then this is what i would do,

1. restore all datafiles from recent backup

2. mount the db

3. do a cancel based recovery (recover database until cancel)

4. open the db with resetlogs (alter database open resetlogs)

5. take an immediate backup of the database (hotbackup), as your previous backup becomes useless due to step #4.

hth,
Stan
Hunan_1
Frequent Advisor

Re: redo log corrupted

The problem is that we I don't have any backup.
So the only I want to save is the database structure, no matter if the stored data is lost.

thanks
Stan_17
Valued Contributor

Re: redo log corrupted

Oops, no backups is always a problem. okay tell me on what datafile your getting the error, is it temp, system or rbs or data...?

do you have any export dumps ?

Stan
Hunan_1
Frequent Advisor

Re: redo log corrupted

That datafile it's attached to the tablespace system.

can I edit the init.ora and use this?

_allow_resetlogs_corruption=TRUE

Could it be an option to get back my database?
Stan_17
Valued Contributor

Re: redo log corrupted

Since the datafile being reported belongs to system tbs and you have no backups..then i would suggest to use the undocumented parameter _allow_resetlogs_corruption=TRUE. only trump card that you have now.

so go ahead, set this parameter in init.ora file and bounce the db.

immediately, take an export dump of the entire database or at least the schemas that your concerned of and rebuild the database.
Brian Crabtree
Honored Contributor

Re: redo log corrupted

This command should work:

alter database clear logfile '';

You might have to do:

alter database clear unarchived logfile '';

The last option that you could try, is to copy the valid member from the group over the corrupted member from the group, and bring the database up. This should allow the database to come up as well.

Brian