We regularly apply the CPU to our oracle homes. Recently we have built out an rac environment and I have been asked to apply the Jan 2009 CPU. I see that the April 2009 CPU does not apply to the ora_crs_home, but I can not find any info regarding applying the Jan 09 CPU the the crs home? I'm hoping some other dba has had this question before me and can provide some guidance. I know very little about crs. Is it necessary to apply CPU patches to the crs home?
I haven't worked with RAC, so I can't answer your question directly. However, since the CPUs are cummulative, can you just apply the April CPU? You already know the answer on whether it needs applied to the CRS home.