steps to hardware migration (DRP)

Hello

we are working in our disaster recovery plan an we are planning to do full copies of our servers and to have identical servers od profuction and replication obviously not at the same time, we are usin a special tool to replicate it,

but we have some doubts, we will have same systems in diferent hardware but this not a migration is an schema oo DRP so i wondered whah will hapen with licenses?

should we have to ask for new licenses for drp servers?

what kind of licenses we have to install?

regards