These servers are connected through a fiberchannel network to a SAN and have a fiber channel LUN assigned.
If this same SAN is presented to your ESXi hosts, then you could present it to the VM fileserver there as a RDM. This would be very fast, in comparison to almost any other approach you will use to copy that much data.
I use this same setup for several 3TB+ volumes connected to a Windows file server with no real issues.
Think about your backup strategy too - with this amount of data, the backup strategy could make certain decisions for you.