Saturday, June 20, 2009

ORA-29702 - Starting RAC instance in non-rac mode

Assume the following situation: Due to some OS or network related problem you are not able to start-up the CRS (this does happen!) before it impacts the database availability and subsequently your business. Your primary goal now is to make the database available as soon as possible irrespective of its mode (RAC or Non-RAC). The reason being you would like to reduce the impact to your business. If you attempt to startup the instance without CRS, you get the following error:

SQL> startup;
ORA-29702: error occurred in Cluster Group Service operation

This error message indicates that it can't start the instance since CRS is not available. Here is the quick work-around to startup the instance. The option is to remove RAC option from your binaries and start the instance. Once you have resolved the CRS related issues, you can turn-on the RAC option back (of course, your instance needs to be down while to turn-on or turn-off the options). Here is how we turn-off:

cd $ORACLE_HOME/rdbms/lib
make -f rac_off ioracle

Set cluster_database=false

You should now be able to startup the instance without CRS stack being up and running.

SQL> Select * from v$option where parameter like 'Real%';

---------------------------------------- ----------
Real Application Clusters FALSE
Real Application Testing TRUE

Turn-on the RAC option with:

make -f rac_on ioracle

Alternatively, you can install a non-rac oracle binaries to quickly start the instance.

By the way, you turn off other options in similar way such as Partitioning (part_on/part_off), DB Vault (dv_on/dv_off) etc..


Anonymous said...

Thank you thank you. As Metalink documentation continues to worsen, posts like this are a godsend.

Anonymous said...

thanks for this wonderful post....I created a rac environment using vmware server. I then created a single instance. The single instance received the same error when I restart the database. By following this instructions, I am able to get my single instance started. Thanks again...

Anonymous said...

thanks for the wonderful post.

Anonymous said...

Fyi, rather than take a long outage to relink with RAC, you can shorten it by just copying back the previously linked oracle binary like this (shutdown the database first!):

cp oracle oracle_racoff
cp oracleO oracle

This assumes you haven't rebuilt the oracle binary for some other reason. Each time the oracle binary is built, it moves the old oracle file to oracleO as a backup. said...

This is an excellent article.
Still, if you want something more hands-on, try these:

You can find more demos (including dataguard, goldengate, streams) there at

Vladimir Grigorian

Anonymous said...

Thanks a lot, This really helped.