Q: Sudden NAS Volume Unmounted

Lately, I am having trouble with running backups of my data to my NAS. I use Chronosync to do this, but in the middle of the backup, it will fail with a "General I/O Error" message.

I don't typically sit there watching my screen while the backup is running (it can take a few hours at times). However, while debugging this issue with Chronosync support, I did. I noticed that just before Chronosync fails, a Mac popup window appears that says "Server connections interrupted: Backup" for a few seconds, then disappears. Besides the backup failing, nothing else apps to be affected. Even the volume is still accessible (I assume it is automatically reconnecting again).

Tonight, I was looking at the Console logs, and I noticed this:

8/16/16 10:51:08.495 PM KernelEventAgent[102]: tid 54485244 type 'smbfs', mounted on '/Volumes/Backups', from '//brett@nas._smb._tcp.local/Backups', not responding

8/16/16 10:52:03.707 PM KernelEventAgent[102]: tid 54485244 type 'smbfs', mounted on '/Volumes/Backups', from '//brett@nas._smb._tcp.local/Backups', dead

8/16/16 10:52:03.708 PM KernelEventAgent[102]: tid 54485244 force unmount //brett@nas._smb._tcp.local/Backups from /Volumes/Backups

So it seems that my MacBook is hanging or something with the NAS (even thought it is actively writing files to it), and is unmounting it, which then causes the Chronosync backup to fail.

Does anyone know why this may be happening, and how to prevent/fix it?