Outsource User Folder to NAS

I want to do something what I suppose should be something I might not be the only one interested in - but I haven't found a proper solution in any forum how to realize it. It's the following:

Outsource my complete user folder (users/myname) from my Local Harddisk to my NAS so it is automounted via Network at startup.

I have a Synology DiskStation which supports SMB and AFP and I want to connect via SMB or AFP.

I have been trying around with AutoFS but was not successful yet. My current auto_master file look like this:

#

# Automounter master map

#

+auto_master # Use directory service

/net -hosts -nobrowse,hidefromfinder,nosuid

/home auto_home -nobrowse,hidefromfinder

/Network/Servers -fstab

/- -static

/- auto_smb

-> I have added the bottom entry which redirects to the auto_smb entry which looks like this:

/users/myname -fstype=smbfs ://admin:password@192.168.1.140/myname

This entry replaces the existing home folder with the one on the NAS.

When I restart, it gives me the error message that I don't have the necessary permissions.

Replacing only specific subfolders of my user folder (e.g. downloads, movies) works perfect - but replacing the whole user folder does not work.

Would be great if anybody could help me with this problem.