[oracle@mydata ~]$ sqlplus / as sysdba
SQL> shutdown immediate
SQL> exit
[oracle@mydata ~]$ lsnrctl stop
rm -rf /u01/app/oracle/*
rm -rf /u01/app/grid/*
rm -rf /u01/app/11.2.0/grid/*
rm -rf /u01/app/oraInventory/*
rm -f /usr/local/bin/dbhome
rm -f /usr/local/bin/oraenv
rm -f /usr/local/bin/coraenv
rm -f /etc/oratab
rm -f /etc/oraInst.loc
rm -rf /etc/oracle/ocr.loc
rm -f /var/tmp/.oracle
[root@mydata ~]# userdel -r oracle
[root@mydata ~]# userdel -r grid
[root@mydata ~]# groupdel oinstall
[root@mydata ~]# groupdel dba
dd if=/dev/zero of=/dev/mapper/iscsi-data bs=1024 count=2056
dd if=/dev/zero of=/dev/mapper/iscsi-fra bs=1024 count=2056
dd if=/dev/zero of=/dev/mapper/iscsi-ocr1 bs=1024 count=2056
dd if=/dev/zero of=/dev/mapper/iscsi-ocr2 bs=1024 count=2056
dd if=/dev/zero of=/dev/mapper/iscsi-ocr3 bs=1024 count=2056