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Don't create the directory stucture yourself.
Linuxmce should detect the second drive and ask you wehter it should use the LinuxMCE sturcture - answer yes and you are done. After that you should be able to find the samba shares using \\dcerouter on an PC in the linuxmce network.
Then copy it from the PC using samba to the Linuxmce server.
Or just setup your NAS to DHCP (client) and insert it in your Linuxmce network. It should then be detected and same question as above is asked. The answer is the same