Zentyal
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Changing the REALM
Sometimes it can be necessary to alter the realm (kerberos). This will brake all user related modules and forces them to reinstall:
/usr/share/zentyal-users/reinstall
Then klick on the "Ally"-Button on the upper right corner of the web-interface.
Then go to "Users" -> "Mode...", change the realm and apply.
Then you have to reenable the "Users"-module and apply the changes.
Then you can also reenable the "Samba"-module and apply the changes.