There are a lot of differences between 10gR2 and 11gR2 RAC, so I wouldn't consider the upgrade to be an easy thing.
Personally, I would prefer to do a fresh installation on a new machine and move the stuff across, but I can appreciate this is not for everyone.
There are a number of issues I can see you facing, including:
- The new grid infrastructure can't run on the same machine as any other version of clusterware, which means dual-running is going to be an issue.
- Lack of support for raw devices may be an issue, although Oracle do support them for upgrades. Even so, I wouldn't consider using them for 11gR2.
- The networking implications are a little different with the inclusion of the SCAN.
- It takes a lot more memory. Make sure you are happy about using up at least another 1-1.5G of RAM per node. If your nodes are already using most of the memory, you need an memory upgrade before upgrading to 11gR2.
If you are still interested in trying, this My Oracle Support note (Complete Checklist for Manual Upgrades to 11gR2 [ID 837570.1]) has a list of steps. I don't like the look of it myself.
It seems 11gR1 is basically the same as 10gR2.. It makes you wonder why they bother with the first release..
I have found plenty of articles covering rolling upgrades to 11gR1 but not 11gR2.. little wonder as its such a different beast.
Probably best to do a fresh install and migrate as you say.
The feeling I get from people from Oracle is that they would have liked 11gR1 RAC to be like this, but it wasn;t ready in time. As a result they were left with waiting for 12g (maybe another 2 years) or release it in 11gR2. You know the decision.
My issue with what they have done is those people who are on 11gR1 RAC and thing the upgrade to 11gR2 RAC is going to be straight forward. They will need to do it for terminal release support, but it's not as simple as previous second release upgrades.
Don't get me wrong, I'm not saying you can't upgrade, I'm just saying 11gR2 RAC is a lot different, so you've got to be careful and know what you are doing. Just upgrading and expecting everything to be the same is unlikely. As I've already said, you'll be losing 1-1.5G of memory per node as part fo the process.
I am currently at Oracle RAC version 10.2.0.4 on HP-UX Itanium OS version 11.23
For 11gR2 it is required the OS at version 11.31 on HP-UX Itanium.
I first backed up on the Oracle related files from the root system then had the SysAdmin upgraded the OS to version 11.31
I restored the Oracle files in the root file system and reboot the boxes (2 nodes RAC)
The CRS 10.2.0.4 does not come up.
Oracle does support for OS 11.31 for 10gR2 on HP-UX Itanium.
Any commnent on this. We thought that We will do this first step and make sure 10gR2 is still running on OS 11.31 before we install the grid infrastructure.
Thanks in advance,
We were able to get the CRS and RAC DBs on Oracle version 10.2.0.4 started after we upgrade from HP-UX Itanium 11.23 to 11.31.
Now I will go through the upgrade process to 11gR2.