By default, you can only create eight NFS mounts per ESXi server. Although this limit can be increased up to 256 by using the advanced NFS.MaxVolumes setting, increasing this limit would generally require an increase in the minimum amount of VMkernel TCP/IP heap memory. The minimum heap memory value can be specified using the advanced Net.TcpipHeapSize setting. You can also set the maximum amount of heap size by using the advanced Net.TcpipHeapMax setting.