Problem: Installer reports INS-20802 while updating the inventory during install of 11.2 Grid Infrastructure (Doc ID 1241054.1)

This problem happened to me during the latest installation and was quite easy to solve. This problems appears because the inventory file in oraInventory is corrupted by leaving open character most probably. In such case perform the following steps:

1. remove the old, incorrect CRS home entry from the inventory.xml:

/u01/app/11.2.0.2/grid/oui/bin/runinstaller -detachHome -local ORACLE_HOME=/u01/app/11.2.0/grid

2. rerun the failed “attachhome” command:

/u01/app/11.2.0.2/grid/oui/bin/runInstaller -attachHome -noClusterEnabled ORACLE_HOME=/u01/app/11.2.0.2/grid ORACLE_HOME_NAME=Ora11g_gridinfrahome1 "CLUSTER_NODES={RACNODE1,RACNODE2,RACNODE3}" "INVENTORY_LOCATION=/u01/app/oraInventory" LOCAL_NODE=RACNODE2

3. mark the new home as the CRS home (CRS=true):

/u01/app/11.2.0.2/grid/oui/bin/runinstaller -local -updateNodeList ORACLE_HOME=/u01/app/11.2.0.2/grid "CLUSTER_NODES={RACNODE1,RACNODE2,RACNODE3}" CRS="true"

4. in the (still open) installer windows click “ok” the acknowledge the error and then select “retry” in the following screen.

Source: metalink – ID 1241054.