DB13 online back Issue in MSCS

Hi Experts,

We have Install SAP CRM for one of our client in MSCS cluster Environment , Production server is goes live ,But now we have faced one issue which is very critical ,

We are trying to schedule the backup using DB13 , Our DB is 11.2.0.4 with OFS 4.1 , But its getting cancelled , For resolving the above issue we followed SAP NOTE 1764650  and install Gateway ,

Now we are able to take Backup when Our DB and sap Role both is on Node1 ,

But we are not able to take backup if DB role or SAP role is on Node2 and vice versa also We are not able to take backup when SAP and DB role both on Node2

Please revert on how to resolve the issue.

Regards

Rableen