netbackup duplication from disk to tape using slp and destaging

True - it is best practice to NOT zone disk WWPN target and tape WWPN target to the same server/appliance initiator WWPN.

It also used to be best practice - for some older HBAs - to also not mix tape and disk on the same dual port HBA - but this is less and less true these days with more modern HBAs.  So, most sites do now mix tape and disk on the same server side dual port HBA card, but just NOT on the same HBA port.

If your server has two dual port HBAs, and thus four initiator ports, and you have dual (resilient) fabric SAN design, then perhaps you can do this:

server HBA1 port 1 initiator - disk target - fabric A

server HBA1 port 2 initiator - tape target - fabric B

server HBA2 port 1 initiator - tape target - fabric A

server HBA2 port 2 initiator - disk target - fabric B