I passed some hours today (rebooting ten times a server can be frustrating …) to search why the cifs share were not mount at boot on a one of my servers.

The mount command was successful when I launched it manually.

A comment of this post recommend to disable the asynchrone mode but it didn’t work for me.

I suspect the problem come from the fact we use a bridge interface for the network, and the mount operations are maybe launched before the “real” ready state of the interface

So I add a sleep time to the /etc/network/if-up.d/mountnfs script.

mount -a -t$NETFS

become

sleep 30
mount -a -t$NETFS

and it works …