Deinstall of Oracle Grid - Metalink 1570358.1

Following a failed upgrade on grid from 12.1 to 12.2 (test box)

Ran the “Upgrade Oracle Grid Infrastructure” from gridsetup.sh which ran successfully; however when running the root.sh script we hit :

The log of current session can be found at:
/u01/app/crsdata/odw01/crsconfig/roothas_2020-04-17_04-23-08AM.log
PROTL-4: Failed to retrieve data from the local registry
2020/04/17 04:23:26 CLSRSC-169: Failed to create or upgrade OLR
Died at /u01/app/product/12.2.0/gridhome_1/crs/install/oraolr.pm line 495.

The command 

'/u01/app/product/12.2.0/gridhome_1/perl/bin/perl -I/u01/app/product/12.2.0/gridhome_1/perl/lib -I/u01/app/product/12.2.0/gridhome_1/crs/install /u01/app/product/12.2.0/gridhome_1/crs/install/roothas.pl ' execution failed

Checked for possible fixes but did not want to run any patches or unsupported fixes without going through Oracle (did not want to cause further probs).

We ran the deinstall tool for the Grid Home 12.2 (which by that point had updated the inventory) which ran successfully. This was to go back to 12.1

However, when we started everything back up the “crsctl stat res -t” was reporting missing “targets” specifically missing ASM diskgroups – very strange. 

When we checked the ASM parameters in the ASM instance, some were empty. 

SQL> show parameter asm

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
asm_diskgroups string DATA
asm_diskstring string /dev/oracleasm/disks
asm_power_limit integer 1
asm_preferred_read_failure_groups string 

The deinstall seems to be more than just remove the s/w gird directory.

More on Metalink here :

How to Reconfigure Oracle Restart on 12c / 12.1 (Doc ID 1570358.1)

Followed this document – back with everything working 😊

Handy Metalink doc to know about if you ever need to remove Oracle grid - hence the note here.