Without CRS/RAC no problem - been there done that. But you don't have ocssd so I assume it's not your case. With cluster... well, can only speculate... If you setup only Oracle database binaries - nothing will happen to existing CSS daemon. 10.2 can either work linked as not RAC or will not work linked with RAC (requires CRS to be at least the same version or higher). How it won't work - no idea but I guess you simply won't be able to open/mount/start the database... or maybe even linking will fail. The correct path with upgrade of the RAC cluster from 10.1 to 10.2 is to first upgrade CRS to 10.2 and then [optionally] install 10.2 Oracle home and upgrade 10.1 database(s) or create new one(s). You can also use 10.1database with 10.2 CRS (well, in theory... also works on our test Linux cluster - no issues noticed). 2006/4/10, LiShan Cheng <exriscer@xxxxxxxxx>: > > Hi > > I was wondering what would happen if I install Oracle rdbms 10.2 in a > server with a 10.1 running? What will happen with ocssd? > > TIA > > > LSC > > -- Best regards, Alex Gorbachev