Samba


Samba uses the SMB protocol to share files and printers across a network connection. Operating systems that support this protocol include Microsoft Windows (through its Network Neighborhood), OS/2, and Linux.

Why Use Samba?

Samba is useful if you have a network of both Windows and Linux machines. Samba will allow files and printers to be shared by all the systems in your network. If you want to share files between Red Hat Linux machines only, refer to the previous section. If you want to share printers between Red Hat Linux machines only, refer to Chapter 8.

Configuring Samba

Samba uses /etc/samba/smb.conf as its configuration file. If you change this configuration file, the changes will not take effect until you restart the Samba daemon with the command service smb restart. The default configuration file (smb.conf) in Red Hat Linux 8.0 allows users to view their Linux home directories as a Samba share on the Windows machine after they log in using the same username and password. It also shares any printers configured for the Red Hat Linux system as Samba shared printers. In other words, you can attach a printer to your Red Hat Linux system and print to it from the Windows machines on your network.

To specify the Windows workgroup and description string, edit the following lines in your smb.conf file:

workgroup = WORKGROUPNAME server string = BRIEF COMMENT ABOUT SERVER 

Replace WORKGROUPNAME with the name of the Windows workgroup to which this machine should belong. The BRIEF COMMENT ABOUT SERVER is optional and will be the Windows comment about the Samba system.

To create a Samba share directory on your Linux system, add the following section to your smb.conf file (after modifying it to reflect your needs and your system):

[sharename] comment = Insert a comment here path = /home/share/ valid users = tfox carole public = no writable = yes printable = no create mask = 0765

The above example allows the users tfox and carole to read and write to the directory /home/share, on the Samba server, from a Samba client.

Samba Passwords

In Red Hat Linux 8.0, the use of encrypted passwords is enabled by default because it is more secure. If encrypted passwords are not used, plaintext passwords are used, which can be intercepted by someone using a network packet sniffer. It is recommended that encrypted passwords be used. The Microsoft SMB Protocol originally used plaintext passwords. However, Windows 2000 and Windows NT 4.0 with Service Pack 3 or higher require encrypted Samba passwords. To use Samba between a Red Hat Linux system and a system with Windows 2000 or Windows NT 4.0 Service Pack 3 or higher, you can either edit your Windows registry to use plaintext passwords or configure Samba on your Linux system to use encrypted passwords. If you choose to modify your registry, you must do so for all your Windows NT or 2000 machines — this is risky and may cause further conflicts.

To configure Samba on your Red Hat Linux system to use encrypted passwords, follow these steps:

  1. Create a separate password file for Samba. To create one based on your existing /etc/passwd file, at a shell prompt, type the following command:

    cat /etc/passwd | mksmbpasswd.sh > /etc/samba/smbpasswd
  2. If the system uses NIS, type the following command:

    ypcat passwd | mksmbpasswd.sh > /etc/samba/smbpasswd
  3. The mksmbpasswd.sh script is installed in your /usr/bin directory with the Samba package.

  4. Change the permissions of the Samba password file so that only root has read and write permissions:

    chmod 600 /etc/samba/smbpasswd
  5. The script does not copy user passwords to the new file. To set each Samba user’s password, use the command (replace username with each user’s username):

    smbpasswd username 
  6. A Samba user account will not be active until a Samba password is set for it.

  7. Encrypted passwords must be enabled in the Samba configuration file. In the file smb.conf, verify that the following lines are not commented out:

    encrypt password = yes smb passwd file = /etc/samba/smbpasswd
  8. Make sure the smb service is started by typing the command service smb restart at a shell prompt.

  9. If you want the smb service to start automatically, use ntsysv, chkconfig, or Services Configuration Tool to enable it at runtime. Refer to Chapter 13 for details.

    Tip

    Read /usr/share/doc/samba-version/docs/htmldocs/ENCRYPTION.html to learn more about encrypted passwords (replace version with the version number of Samba that you have installed).

The pam_smbpass PAM module can be used to sync users’ Samba passwords with their system passwords when the passwd command is used. If a user invokes the passwd command, the password he or she uses to log in to the Red Hat Linux system and the password he or she must provide to connect to a Samba share are changed. To enable this feature, add the following line to /etc/pam.d/system-auth below the pam_cracklib.so invocation:

password required /lib/security/pam_smbpass.so nullok use_authtok try_first_pass

Connecting to a Samba Share

To connect to a Linux Samba share from a Microsoft Windows machine, use Network Neighborhood or Windows Explorer. To connect to a Samba share from a Linux system, type the following at a shell prompt:

smbclient //hostname/sharename -U username 

You will need to replace hostname with the hostname or IP address of the Samba server you want to connect to, sharename with the name of the shared directory you want to browse, and username with the Samba username for the system. Enter the correct password or press Enter if no password is required for the user.

If you see the smb:\ prompt, you have successfully logged in. Once you are logged in, type help for a list of commands. If you wish to browse the contents of your home directory, replace sharename with your username. If the -U switch is not used, the username of the current user is passed to the Samba server. To exit smbclient, type exit at the smb:\ prompt.

You can also use Nautilus to view available Samba shares on your network. On the GNOME desktop, go to the Main Menu Button (on the Panel) > Home Folder to open a Nautilus window. Type smb: in the Location: bar. You will see an icon for each available SMB workgroups on your network. To access one, double-click the icon for it.

If the SMB share you are connecting to requires a user name and password combination, you must specify them in the Location: bar using the following syntax (replace user, password, servername, and sharename with the appropriate values):

smb://user:password@servername/sharename/




Official Red Hat Linux Administrator's Guide
Official Red Hat Linux Administrators Guide
ISBN: 0764516957
EAN: 2147483647
Year: 2002
Pages: 278
Authors: Red Hat Inc

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