Newly added hard disk through VCenter webclient on a VM not showing on the guest OS (Linux)

Hi,

I added a 16TB disk through VCenter Web client on a VM (ubuntu) hosted by a ESXi 6.0 host, but the disk is not showing up on the guest OS disks list. This disk is using the netapp NFS for data storage. I can SSH into the Host and the VM, dont know how to view the vmdk file on that VM. basically just need the UUID of the newly added Disk on the VM, do we need to reboot the OS or the VM for the newly added hard disk to show-up in the list of disk?

Please advise.

Thanks