Oracle ASM diskgroup problems

Hi all,

DB: 10.2.0.3 using ASM
O/S: Windows

We have a database that has been set up with 2 ASM diskgroups: DATA and ONLINELOG. The ONLINELOG diskgroup holds all the archive redo logs and some online redo log members. During the weekend gone the alert log complained that the ONLINELOG diskgroup disk space had been exhausted whilst Oracle was trying to archive logs. This eventually led to the ASM instance being terminated.

Wehave managed to get to database back up in mount state. However we cannot mount the ONLINELOG diskgroup as Oracle is complaining of a disk write lost failure (ORA-15096: lost disk write detected ). This means that a failure either by disk hardware or disk software caused a disk write to be lost, even though ASM received acknowledgement that the write completed.


The official solution mentions that the diskgroup is corrupt and cannot be recovered. The disk group must be recreated, and its contents restored from backups. We don’t have any backups (this solution is not managed by us, we are trying to help another part of the company). Hence, my question here is there anyway we can open the database? (There are some members of the online redo logs on the available diskgroup)

Any help will be highly appreciated,

Thanks,
Nikesh

Hi

Do you mean to say that some members of the online redo log groups are available on another diskgroup ?

regards
Hrishy

Hi Hrishy,

I think 2/3 groups are available on the available diskgroup but the 'current' logfile is in the damaged diskgroup. Is it possible to recreate the control file and just point to the logs available and try to open the database?

Thanks

Just wanted to add, i think there are 5 groups with one member each (i am saying 'i think' because i dont have access to the system and am going by what i have been told)

Hi

First find out if you have multiplexed online redologs with each member in different disk groups.

http://download.oracle.com/docs/cd/B...rios.htm#11729

Ahh the most important thing is before you attempt any recovery
a)Keep a CoolHead dont panic
b)take a backup of whatever is remaining so in case you screw up you get back to whateever state you were before the screw up :-)
c)Contact oracle support before attempting a recovery after all thats why we pay oracle support for ;-)


Last resort you need to try something called as oracle DuDe which can extract data from a database like this
:-)

regards
Hrishy

Thanks Hrishy,

Yes they are taking a backup
They have contacted Oracle support and they have mentioned force opening the database using a hidden parameter which may allow for corruption. Once open, export out the data needed. This is their case might not be feasiable time wise due to the huge amounts of data in the tables

What is Oracle DuDe??
:)

Thanks,
Chucks

Hi

http://www.ora600.nl/introduction.htm

I am not sure if they have support for ASM

regards
Hrishy

Hi Hrishy,

If they manage to open the database (using the hidden parameter), the application data is organised in weekly tablespaces with daily partitions. Hence if they do manage to open the db will they be able to take exports of weekly tablespaces from a certain date (as long as datafiles are online and consistent) and plug them into a new database? Under normal circumstances this would would work but as all the data is partitioned would the base tables have to exported as well?

You can export at the partition level and then import those partitions into a table in a new database.