We used SLES like that on our HPC. SLES and RH will run just fine without subscriptions if you don't plan to update them. The license for RH precludes you from

We used SLES like that on our HPC. SLES and RH will run just fine without subscriptions if you don't plan to update them. The license for RH precludes you from running unlicensed RH, if you have any licensed RH. I don't believe SuSE does the same.