The cifs-name
manual page which is accessible from the System Management Unit (SMU) GUI or the HNAS console explains the syntax that is expected:
cifs-name add -m ads [ -a <dc ipaddr> ] [ -f <folder> ] [ -p <dns suffix> ] <name 1> ... where ... -f, --folder <folder> ADS directory folder to place new machine account in. Value may be either DNS-style ("suborg.midorg.toporg") or an RDN sequence ("ou=suborg,ou=midorg,ou=toporg"). Default is "cn=Computers". The domain's base DN is automatically appended and may not be explicitly given. ... cifs-name add -m ads -a 10.2.1.123 -f "ou=midorg, ou=toporg" ads-name2 cifs-name add -m ads -a 10.2.1.123 -f midorg.toporg my-ads-name3
If this is not working then I suggest that you open a support case so that we can help you investigate further.