The only work around I have found for this endurance problem is to restart the player. The easy way to do that is to change the Output DAC choice in Settings and save the settings. This kicks of a player restart, which unexplainably causes reconnection to the Mac OS Music NAS share. At least there is a workaround from the “remote control” (web browser) that doesn’t require manually power-cycling the rPI.
Forcing the player to restart by switching the output does not reliably force reconnection to the NAS. However, unplugging the DAC and reconnecting it causes system to reconfigure and the player to restart. This causes Volumio to reconnect to the Mac OS Share and an update scan to be started. Power-cycling the PI to reboot it successfully reconnects to the Mac OS Share as well.
So I have not found a work-around other than turning the power off when not using Volumio and turning it back on manually each time I want to use it.
I’m noting, however, that simply pulling the power from the PI will not gracefully release the SMB connection from the Mac and so the Mac will not sleep, thinking it has an active sharingd client connection. Toggling File Sharing off and on fixes that lingering connection on the Mac, but this is highly tedious.
For Future Consideration:
A “standby” setting in the Volumio state machine. When entering Standby, the Volumio would release NAS connections. When leaving Standby, Volumio would reconnect to NAS libraries. No auto-update when leaving standby. A settable timeout with no activity causing Volumio to enter Standby. Web interface should enable forcing Volumio into and out of Standby. Other music streamers support this Standby facility. (See e.g. Yamaha WXC-50)
And there should be a checkbox to connect and disconnect a particular NAS to enable graceful network reconfiguration.
There are also bugs in editing the NAS setup. If you try to Edit then Save an existing NAS definition (even if changing nothing) it complains that “mkdir” fails when adding a new network drive. This seems to be related to the authentication error as I can successfully change settings while the drive is connected (it just reconnects and forces an Update).
I do hope folks with Mac OS Folder Sharing find this at least somewhat explanatory, if not super helpful. And I hope @Volumio will add the Standby feature set to the roadmap for the future.