After looking at your log a little closer, you have several things going on here. The ping issue is probably from starting unRAID and the VM not running. When UD starts it cannot ping the VM. I suspect your share is set to auto mount. After the VM is running, the ping is successful because a mount is attempted.
After some time I suspect you are then trying to mount the share and get the file not found error.
The issue you need to concentrate on is the 'No such file or directory' error on the server. I don't know how you have the VM set for NFS sharing, but that's the heart of your problem.