The following command hangs :

$cd /u01/app/19.0.0/grid/
$./runcluvfy.sh Stage -pre crsinst -n node1,node2 -verbose 

SOLUTION

$ cat /etc/redhat-release
Red Hat Enterprise Linux release 8.6 (Ootpa)

As workaround:
         $export CV_ASSUME_DISTID=OEL7.8

$./runcluvfy.sh stage -pre crsinst -n node1,node2 -verbose

Or

Use the latest Cluster Verification Utility (CVU) (Doc ID 2731675.1)

 Patch 30839369