Mapping usernames with the or features of Samba can be relatively expensive. During login of a user, the mapping is done several times. In particular, calling the can slow down logins if external databases have to be queried from the script being called. The parameter controls a mapping cache. It specifies the number of seconds a mapping from the username map file or script is to be efficiently cached. The default of 0 means no caching is done. 0 60