Best way to upgrade redhat 7,9 to 8.x on both netbackup master and media servers

[spiritme_dz]

Hi,

We need your advice regarding the best way to upgrade from redhat 7.9 to redhat 8.x on both Master and Media virtual servers. 

We need this task to be done before the Netbackup update to 10.4 version.

We are running Netbackup 10.0.0.1 with rehdat 7.9 (Red Hat Enterprise Linux Server release 7.9 (Maipo))  

Thanks!