CLUVY heavily depends on the oraInventory; without which you will get the olsnodes missing error.
To check the oraInventory health simple commands as below are used
If you do endup losing the inventory or corrupting it, it can be rebuild online without taking the DB or the clusterware down.
It is recommended to detach and attach the home back and the oraInventory should be preferably kept local on each node. I would also recommend DBAs tar and save the oraInventory once in a while.
In the below example GI is the Grid home with cluterware and ASM and ORACLE_HOME the RDBMS home
The below needs to be run on each node.
$GI_HOME/oui/bin/runInstaller -detachHome -silent -local ORACLE_HOME=$ORACLE_HOME
$GI_HOME/oui/bin/runInstaller -silent -local -ignoreSysPrereqs -attachHome ORACLE_HOME=$ORACLE_HOME ORACLE_HOME_NAME='11gR2DB1' LOCAL_NODE=
$GI_HOME/oui/bin/runInstaller -silent -local -ignoreSysPrereqs -attachHome ORACLE_HOME=$GI_HOME ORACLE_HOME_NAME='11gR2GI1' LOCAL_NODE=racnode1 CLUSTER_NODES=racnode1,racnode2 CRS=true
Note GI home is the only one which should have CRS=TRUE set.
The Oracle Home names can be found under
where is the
#Wed Sep 07 15:59:40 BST 2011