Oracle rac 是不支持一個節點是rhel5.x ,另一個節點是rhel6.x的
因為rhel5.x 和rhel 6.x 在oracle看來,是“different operating system versions”
oracle 解決sr的工程師給的答復全文如下：
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
我的補充：以上的英文答復沒有考慮asm磁盤組的構成方式（asmlib or raw）。
而rhel 5.5 和rhel 5.8 的差異，僅僅是os patch bundle，rhel 5.5 和rhel 5.8 有相同的operating system versions。
延伸一下：對於windows 下的rac而言，比如說一個2個節點的windows rac，其中一個節點是windows 2003， 那麼另外的一個節點就不能是windows 2008.
