Synology NAS unmounts itself

I recently purchased a Synology NAS. It's great when it's working, however every time I wake my iMac from sleep I have to remount the drive before being able to access it. It is literally not connected anymore when I resume. This is causing all sorts of havoc with my iTunes library.

This is probably a setting or something I have wrong either on the NAS on my iMac or I am connecting to it in the wrong way.

Any ideas?

If anyone else has the same problem I seem to have had luck with the following entered into terminal:


You will have to enter your password.