I have a Netapp in gateway mode and I am in a situation that I need to refresh the backend storage array. What would be the best approach to decom the current array LUNs with minimal or none downtime ? Thank You !
This depends on which Data ONTAP version and licenses you have and how much downtime you can afford. Sync mirror is zero downtime, but IIRC it is not supported between different vendors. Vol move is zero downtime but works for LUN only. Snap mirror offers the least downtime but requires license. Otherwise vol copy works always but means no client access for the copy duration.
Other considerations are whether you have existing vault relationships etc. pulling in professional service may be the best approach.
vol move 7-Mode is only for SAN data... snapmirror would be a quick cutover otherwise but a short downtime window. The 7-Mode root volume will need a takeover/giveback to move but that can be done quickly.
Are you running MultiStore or vFilers? They work great for this using data motion for vFilers or vFiler migrate to move the vFiler between controllers (and back or just leave them swapped) when swapping out back-end arrays.