When I patched grid infra (GI) and oracle home (OH) of an Oracle RAC database by opatchauto, I got OPATCHAUTO-72030: Cannot execute in rolling mode, as CRS home is shared like this:
[root@primary01 ~]# export PATH=$PATH:/u01/app/19.0.0/grid/OPatch
[root@primary01 ~]# opatchauto apply /sources/grid/patches/31750108
OPatchauto session is initiated at Mon Feb 8 16:12:09 2021
System initialization log file is /u01/app/19.0.0/grid/cfgtoollogs/opatchautodb/systemconfig2021-02-08_04-12-18PM.log.
Session log file is /u01/app/19.0.0/grid/cfgtoollogs/opatchauto/opatchauto2021-02-08_04-13-07PM.log
The id for this session is 9Z5G
Shared home /u01/app/19.0.0/grid can only be patched in nonrolling mode.
OPATCHAUTO-72030: Execution mode invalid.
OPATCHAUTO-72030: Cannot execute in rolling mode, as CRS home is shared.
OPATCHAUTO-72030: Execute in non-rolling mode.
OPatchauto session completed at Mon Feb 8 16:14:05 2021
Time taken to complete the session 1 minute, 56 seconds
opatchauto failed with error code 42
I just export an additional environment variable CV_ASSUME_DISTID to solve the problem.
[root@primary01 ~]# export CV_ASSUME_DISTID=OEL8.1
Values like OEL7.6 to OEL7.8 are also workable.
What I think is that opatchauto utility misjudged the real cause which is irrelevant to the rolling mode. I have explained about the environment pretty much in How to Resolve INS-08101 during 19c Installation.