I had a similar problem after an release upgrade from 12.04.3 to 14.04.1.
After the upgrade, only local users could log in and any command was very slooow.
In particular commands like add-user or add-group would never finish.
Removing mentions of ldap in nsswitch.conf seemed to solve the problem.
In the end I discovered that the apparent cause was removing this line from nsswitch:
I had a similar problem after an release upgrade from 12.04.3 to 14.04.1.
After the upgrade, only local users could log in and any command was very slooow.
In particular commands like add-user or add-group would never finish.
Removing mentions of ldap in nsswitch.conf seemed to solve the problem.
In the end I discovered that the apparent cause was removing this line from nsswitch:
passwd_compat: ldap
and using instead
passwd: compat ldap
After this change, everything worked normally.