apply patchset to Oracle RAC

 Hi,

We have production database oracle RAC 10.2.0.2, and want to apply patchset to upgrade to 10.2.0.4. Since it's a busy production, we want to do it safely. From oracle document, it suggests create another oracle_home to apply the patchset. My question is whether we need to create another crs_home since crs also need to be upgraded. And if we don't clone a new crs_home and something goes wrong when doing upgrade oracle_home, will 10.2.0.4 crs_home work with 10.2.0.2 oracle_home? If we clone a new crs_home to apply patchset, will the new crs affect the current one since we have to use the same private and