[INS-08101] Unexpected error while executing the action at state: ‘supportedOSCheck’
Cause:
While grid setup was invoked, there was an error message saying that the OS OEL8 is not compatible to install the software

Workaround:
Check the OS version
[oracle@dgprim01 ~]$ cat /etc/os-release
NAME="Oracle Linux Server"
VERSION="8.4"
ID="ol"
ID_LIKE="fedora"
VARIANT="Server"
VARIANT_ID="server"
VERSION_ID="8.4"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Oracle Linux Server 8.4"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:oracle:linux:8:4:server"
HOME_URL="https://linux.oracle.com/"
BUG_REPORT_URL="https://bugzilla.oracle.com/"
ORACLE_BUGZILLA_PRODUCT="Oracle Linux 8"
ORACLE_BUGZILLA_PRODUCT_VERSION=8.4
ORACLE_SUPPORT_PRODUCT="Oracle Linux"
ORACLE_SUPPORT_PRODUCT_VERSION=8.4
Reduce the OS version to backward compatibility
[oracle@dgprim01 grid]$ export CV_ASSUME_DISTID=OEL8
or
Edit the cvu file
[oracle@dgprim01 ~]$ grep 'DISTID' /app01/grid/cv/admin/cvu_config
#CV_ASSUME_DISTID=OEL8