I don't think this is a full backup, I've tried it and it give me a 4 Gb backup archive but I have 20 Gb data in ibays.
It should be a full backup of the configuration,  users and passwords, custom templates and /home/e-smith/.  Here is the list.
        'home/e-smith',
        'etc/e-smith/templates-custom',
        'etc/e-smith/templates-user-custom',
        'etc/ssh',
        'root',
        'etc/sudoers',
        'etc/passwd',
        'etc/shadow',
        'etc/group',
        'etc/gshadow',
        'etc/samba/secrets.tdb',
        'etc/samba/smbpasswd',
        'etc/smbpasswd',
NOTE: It does NOT backup web apps in the /opt directory.
Please check your smeserver.tgz tar file and determine if the backup is incomplete.  If it is incomplete, report this to the bug tracker.