Oracle ASM diskgroup problems
DB: 10.2.0.3 using ASM
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 donít 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,
Do you mean to say that some members of the online redo log groups are available on another diskgroup ?
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?
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)
First find out if you have multiplexed online redologs with each member in different disk groups.
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
Last edited by hrishy; 05-29-2008 at 06:34 AM.
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??
You can export at the partition level and then import those partitions into a table in a new database.
Pablo (Paul) Berzukov
Author of Understanding Database Administration
available at amazon and other bookstores.
Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.
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