The RPM DB Index check fails when running the pre-upgrade checklist.
Perform the following steps:
1. SSH to the affected component host.
2. Run the below command to move any corrupted rpm to other location (/root).
mv /var/lib/rpm/__db.* /root/
3. Run yum clean all and yum list all using the below command.
yum clean all
yum list all
4. Re-run the pre-upgrade checklist and retry the upgrade procedure from the Admin Server:
upgrade-cli-client –-upgrade --host-addr <IP of NetWitness Server> --version 11.x.x.x