Oracle Grid Infrastructure 18c patching part 3: Executing out-of-place patching with the local-mode automaton

I wish I had more time to blog in the recent weeks. Sorry for the delay in this blog series šŸ™‚

If you have not read the two previous blog posts, please do it now. I suppose here that you have the Independent Local-Mode Automaton already enabled.

What does the Independent Local-mode Automaton?

The automaton automates the process of moving the active Grid Infrastructure Oracle Home from the current one to a new one. The new one can be either at a higher patch level or at a lower one. Of course, you will probably want to patch your grid infrastructure, going then to a higher level of patching.

Preparing the new Grid Infrastructure Oracle Home

The GI home, starting from 12.2, is just a zip that is extracted directly in the new Oracle Home. In this blog post I suppose that you want to patch your Grid Infrastructure from an existing 18.3 to a brand new 18.4 (18.5 will be released very soon).

So, if your current OH is /u01/app/grid/crs1830, you might want to prepare the new home in /u01/app/grid/crs1840 by unzipping the software and then patching using the steps described here.

If you already have a golden image with the correct version, you can unzip it directly.

Beware of four important things:Ā 

  1. You have to register the new Oracle home in the Central Inventory using the SW_ONLY install, asĀ  described here.
  2. You must do it for all the nodes in the cluster prior to upgrading
  3. The response file must contain the same groups (DBA, OPER, etc) as the current active Home, otherwise errors will appear.
  4. You must relink by hand your Oracle binaries with the RAC option:
    $ cd /u01/app/grid/1crs1840/rdbms/lib
    $ make -f ins_rdbms.mk rac_on ioracle

In fact, after every attach to the central inventory the binaries are relinked without RAC option, so it is important to activate RAC again to avoid bad problems when upgrading the ASM with the new Automaton.

Executing the move gihome

If everything is correct, you should have now the current and new Oracle Homes, correctly registered in the Central Inventory, with the RAC option activated.

You can now do a firstĀ evalĀ to check if everything looks good:

My personal suggestion at least at your first experiences with the automaton, is to move the Oracle Home onĀ one node at a time. This way,Ā YOU control the relocation of the services and resources before doing the actual move operation.

Here is the execution for theĀ first node:

From this output you can see at line 15 that the cluster status is NORMAL, then the cluster is stopped on node 1 (lines 16 to 100), then the active version is modified in the oracle-ohasd.service file (line 101), then started back with the new version (lines 102 to 171). The cluster status now is ROLLING PATCH (line 172). The TFA and the node list are updated.Ā 

Before continuing with the other(s) node(s), make sure that all the resources are up & running:

You might want as well to relocate manually your resources back to node 1 prior to continuing on node 2.

After that, node 2 can follow the very same procedure:

As you can see, there are two differencse here: the second node was in this case the last one, so the cluster status gets back to NORMAL, and the GIMR is patched with datapatch (lines 176-227).

At this point, the cluster has been patched. After some testing, you can safely remove the inactive version of Grid Infrastructure using the deinstall binary ($OLD_OH/deinstall/deinstall).

Quite easy, huh?

If you combine the Independent Local-mode Automaton with a home-developed solution for the creation and the provisioning of Grid Infrastructure Golden Images, you can easily achieve automated Grid Infrastructure patching of a big, multi-cluster environment.

Of course, Fleet Patching and Provisioning remains the Rolls-Royce: if you can afford it, GI patching and much more is completely automated and developed by Oracle, so you will have no headaches when new versions are released. But the local-mode automaton might be enough for your needs.

—Ā 

Ludo

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Ludovico

Oracle ACE Director and Computing Engineer at CERN
Ludovico is an Oracle ACE Director, frequent speaker and community contributor, working as Computing Engineer at CERN, the European Organization for Nuclear Research, in Switzerland.

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