When vMA is added to active directory, be default, all users will be able to login to the appliance.
In order to restrict the login to certain users or groups, we need to manually edit the Likewise configuration file located in /etc/likewise/lsassd.conf
Look for the following section, uncomment “require-membership-of” and provide a comma seperated list of users, groups and sid’s that you would like to restrict access to.
# Allow only the following users and groups
# to login to this system
#
# Note: Use a comma-separated list of
# { alias, NT4 style name, SID }
#
# require-membership-of = DEMO\Domain Admins, DEMO\user001, S-1-5-21-234451270-3421269571-2046787926-1116
Restart the appliance after saving the file.