Oracle rac 是不支持一个节点是rhel5.x ,另一个节点是rhel6.x的
因为rhel5.x 和rhel 6.x 在oracle看来,是“different operating system versions”
oracle 解决sr的工程师给的答复全文如下：
There shouldn't be any problem in installing RAC with different patch bundle as long as they are meeting with minimum requirement. Oracle does not support running different operating system versions on cluster members, unless an operating system is being upgraded. You cannot run different operating system version binaries on members of the same cluster, even if each operating system is supported. In your case, it is not a different operating system version so there shouldn't be any problem. However, It is recommended to have both the OS at same patch bundle
我的补充：以上的英文答复没有考虑asm磁盘组的构成方式（asmlib or raw）。
而rhel 5.5 和rhel 5.8 的差异，仅仅是os patch bundle，rhel 5.5 和rhel 5.8 有相同的operating system versions。
延伸一下：对于windows 下的rac而言，比如说一个2个节点的windows rac，，其中一个节点是windows 2003， 那么另外的一个节点就不能是windows 2008.
相反，某天也许你会忽然发现，心早已沦陷。
