How to move the central Inventory (oraInventory) to another location

1- Find the current location of the central inventory (normally $ORACLE_BASE/oraInventory):

For example:

$ find /home/oracle -name oraInventory -print

/u01/app/oracle/oraInventory

2- Open the oraInst.loc file in /var/opt/oracle and check the value of inventory_loc

$ cat /var/opt/oracle/oraInst.loc

inventory_loc=/u01/app/oracle/oraInventory
inst_group=oinstall

Remark: The oraInst.loc file is simply a pointer to the location of the central inventory (oraInventory)
3- Copy the oraInventory directory to the destination directory

$ cp -Rp /home/oracle/oraInventory /app/oracle

4- Edit the oraInst.loc file to point to the new location

For example:

$ vi /var/opt/oracle/oraInst.loc

inventory_loc=/app/oracle/oraInventory
inst_group=dba