1) What is the use of username map?

2) Is it necessary to use passdb backend?

3) I only understand add machine script. What are the use of add/delete user and group script?

Thanks

1) What is the use of username map?
The username map for the client gives automatic domain login access. If you mean server, it defines the read/write/admin priveledges of each user.

2) Is it necessary to use passdb backend?
No, it can use your PAM(local) l/p's. It's just a separate local database if you wanna keep it separate.

3) I only understand add machine script. What are the use of add/delete user and group script?
Making a group called sambawrite or sambaread or sambaadmin will allow you to add users to the group and grant them access to those rights in the directories. Or you can assign it per user if you only have a few users.

Good luck.

1) Sorry I still don't quite understand username map. Goggle-d and found this "2. If your Windows username does not exactly match your UNIX usernames, you must use "username map" to map the Windows user to a UNIX user."
What does that exactly means? Unix username is not samba username right?

2) Whats PAM? If I were to use PAM, where is it located at?

3) Yes I understand about the users and groups permission. But what is the use of those script in smb.conf? I know add machine script is to automatically add the windows's computer name. How about add/delete user/group script?

4) I just remembered theres also this passwd change program in smb.conf right? How does the user change his/her password in windows through this program?

Thanks