Chapter 15. File and Print Servers

This chapter guides you through the installation and configuration of Samba, an open source implementation of the Server Message Block (SMB) and common Internet file system (CIFS) protocol, and vsftpd, the primary FTP server shipped with Red Hat Enterprise Linux. Additionally, it explains how to use the Print Settings tool to configure printers.

15.1. Samba

Samba implements the Server Message Block (SMB) protocol in Red Hat Enterprise Linux. The SMB protocol is used to access resources on a server, such as file shares and shared printers. Additionally, Samba implements the Distributed Computing Environment Remote Procedure Call (DCE RPC) protocol used by Microsoft Windows.
You can run Samba as:
  • An Active Directory (AD) or NT4 domain member
  • A standalone server
  • An NT4 Primary Domain Controller (PDC) or Backup Domain Controller (BDC)
Independently of the installation mode, you can optionally share directories and printers. This enables Samba to act as a file and print server.

Note

Red Hat does not support running Samba as an AD domain controller (DC).

15.1.1. The Samba Services

Samba provides the following services:
smbd
This service provides file sharing and printing services using the SMB protocol. Additionally, the service is responsible for resource locking and for authenticating connecting users. The smb systemd service starts and stops the smbd daemon.
To use the smbd service, install the samba package.
nmbd
This service provides host name and IP resolution using the NetBIOS over IP protocol. Additionally to the name resolution, the nmbd service enables browsing the SMB network to locate domains, work groups, hosts, file shares, and printers. For this, the service either reports this information directly to the broadcasting client or forwards it to a local or master browser. The nmb systemd service starts and stops the nmbd daemon.
Note that modern SMB networks use DNS to resolve clients and IP addresses.
To use the nmbd service, install the samba package.
winbindd
The winbindd service provides an interface for the Name Service Switch (NSS) to use AD or NT4 domain users and groups on the local system. This enables, for example, domain users to authenticate to services hosted on a Samba server or to other local services. The winbind systemd service starts and stops the winbindd daemon.
To use the winbindd service, install the samba-winbind package.

15.1.2. Verifying the smb.conf File by Using the testparm Utility

The testparm utility verifies that the Samba configuration in the /etc/samba/smb.conf file is correct. The utility detects invalid parameters and values, but also incorrect settings, such as for ID mapping. If testparm reports no problem, the Samba services will successfully load the /etc/samba/smb.conf file. Note that testparm cannot verify that the configured services will be available or work as expected.

Important

Red Hat recommends that you verify the /etc/samba/smb.conf file by using testparm after each modification of this file.
To verify the /etc/samba/smb.conf file, run the testparm utility as the root user. If testparm reports incorrect parameters, values, or other errors in the configuration, fix the problem and run the utility again.

Example 15.1. Using testparm

The following output reports a non-existent parameter and an incorrect ID mapping configuration:
~]# testparm
Load smb config files from /etc/samba/smb.conf
rlimit_max: increasing rlimit_max (1024) to minimum Windows limit (16384)
Unknown parameter encountered: "log levell"
Processing section "[example_share]"
Loaded services file OK.
ERROR: The idmap range for the domain * (tdb) overlaps with the range of DOMAIN (ad)!

Server role: ROLE_DOMAIN_MEMBER

Press enter to see a dump of your service definitions

# Global parameters
[global]
	...

[example_share]
	...

15.1.3. Understanding the Samba Security Modes

The security parameter in the [global] section in the /etc/samba/smb.conf file manages how Samba authenticates users that are connecting to the service. Depending on the mode you install Samba in, the parameter must be set to different values:
For further details, see the description of the security parameter in the smb.conf(5) man page.

15.1.4. Setting up Samba as a Standalone Server

In certain situations, administrators want to set up a Samba server that is not a member of a domain. In this installation mode, Samba authenticates users to a local database instead of to a central DC. Additionally, you can enable guest access to allow users to connect to one or multiple services without authentication.

15.1.4.1. Setting up the Server Configuration for the Standalone Server

To set up Samba as a standalone server:

Procedure 15.1. Setting up Samba as a Standalone Server

  1. Install the samba package:
    ~]# yum install samba
  2. Edit the /etc/samba/smb.conf file and set the following parameters:
    [global]
    	workgroup = Example-WG
    	netbios name = Server
    	security = user
    
    	log file = /var/log/samba/%m.log
    	log level = 1
    This configuration defines a standalone server named Server within the Example-WG work group. Additionally, this configuration enables logging on a minimal level (1) and log files will be stored in the /var/log/samba/ directory. Samba will expand the %m macro in the log file parameter to the NetBIOS name of connecting clients. This enables individual log files for each client.
    For further details, see the parameter descriptions in the smb.conf(5) man page.
  3. Configure file or printer sharing. See:
  4. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  5. If you set up shares that require authentication, create the user accounts. For details, see Section 15.1.4.2, “Creating and Enabling Local User Accounts”.
  6. Open the required ports and reload the firewall configuration by using the firewall-cmd utility:
    ~]# firewall-cmd --permanent --add-port={139/tcp,445/tcp}
    ~]# firewall-cmd --reload
  7. Start the smb service:
    ~]# systemctl start smb
  8. Optionally, enable the smb service to start automatically when the system boots:
    ~]# systemctl enable smb

15.1.4.2. Creating and Enabling Local User Accounts

To enable users to authenticate when they connect to a share, you must create the accounts on the Samba host both in the operating system and in the Samba database. Samba requires the operating system account to validate the Access Control Lists (ACL) on file system objects and the Samba account to authenticate connecting users.
If you use the passdb backend = tdbsam default setting, Samba stores user accounts in the /var/lib/samba/private/passdb.tdb database.
For example, to create the example Samba user:

Procedure 15.2. Creating a Samba User

  1. Create the operating system account:
    ~]# useradd -M -s /sbin/nologin example
    The previous command adds the example account without creating a home directory. If the account is only used to authenticate to Samba, assign the /sbin/nologin command as shell to prevent the account from logging in locally.
  2. Set a password to the operating system account to enable it:
    ~]# passwd example
    Enter new UNIX password: password
    Retype new UNIX password: password
    passwd: password updated successfully
    Samba does not use the password set on the operating system account to authenticate. However, you need to set a password to enable the account. If an account is disabled, Samba denies access if this user connects.
  3. Add the user to the Samba database and set a password to the account:
    ~]# smbpasswd -a example
    New SMB password: password
    Retype new SMB password: password
    Added user example.
    Use this password to authenticate when using this account to connect to a Samba share.
  4. Enable the Samba account:
    ~]# smbpasswd -e example
    Enabled user example.

15.1.5. Setting up Samba as a Domain Member

Administrators running an AD or NT4 domain often want to use Samba to join their Red Hat Enterprise Linux server as a member to the domain. This enables you to:
  • Access domain resources on other domain members
  • Authenticate domain users to local services, such as sshd
  • Share directories and printers hosted on the server to act as a file and print server

15.1.5.1. Joining a Domain

To join a Red Hat Enterprise Linux system to a domain:

Procedure 15.3. Joining a Red Hat Enterprise Linux System to a Domain

  1. Install the following packages:
    ~]# yum install realmd oddjob-mkhomedir oddjob samba-winbind-clients \
           samba-winbind samba-common-tools
  2. If you join an AD, additionally install the samba-winbind-krb5-locator package:
    ~]# yum install samba-winbind-krb5-locator
    This plug-in enables Kerberos to locate the Key Distribution Center (KDC) based on AD sites using DNS service records.
  3. Optionally, rename the existing /etc/samba/smb.conf Samba configuration file:
    ~]# mv /etc/samba/smb.conf /etc/samba/smb.conf.old
  4. Join the domain. For example, to join a domain named ad.example.com
    ~]# realm join --client-software=winbind ad.example.com
    Using the previous command, the realm utility automatically:
    • Creates a /etc/samba/smb.conf file for a membership in the ad.example.com domain
    • Adds the winbind module for user and group lookups to the /etc/nsswitch.conf file
    • Configures the Kerberos client in the /etc/krb5.conf file for the AD membership
    • Updates the Pluggable Authentication Module (PAM) configuration files in the /etc/pam.d/ directory
    • Starts the winbind service and enables the service to start when the system boots
    For further details about the realm utility, see the realm(8) man page and the corresponding section in the Red Hat Windows Integration Guide.
  5. Optionally, set an alternative ID mapping back end or customized ID mapping settings in the /etc/samba/smb.conf file. For details, see Section 15.1.5.3, “Understanding ID Mapping”.

15.1.5.2. Verifying That Samba Was Correctly Joined As a Domain Member

After you joined a Red Hat Enterprise Linux as a domain member, you can run different tests to verify that the join succeeded. See:

Verifying That the Operating System Can Retrieve Domain User Accounts and Groups

Use the getent utility to verify that the operating system can retrieve domain users and groups. For example:
  • To query the administrator account in the AD domain:
    ~]# getent passwd AD\\administrator
    AD\administrator:*:10000:10000::/home/administrator@AD:/bin/bash
  • To query the members of the Domain Users group in the AD domain:
    ~]# getent group "AD\\Domain Users"
    AD\domain users:x:10000:user
If the command works correctly, verify that you can use domain users and groups when you set permissions on files and directories. For example, to set the owner of the /srv/samba/example.txt file to administrator and the group to Domain Admins:
~]# chown administrator:"Domain Admins" /srv/samba/example.txt

Verifying If AD Domain Users Can Obtain a Kerberos Ticket

In an AD environment, users can obtain a Kerberos ticket from the DC. For example, to verify if the administrator user can obtain a Kerberos ticket:

Note

To use the kinit and klist utilities, install the krb5-workstation package on the Samba domain member.

Procedure 15.4. Obtaining a Kerberos Ticket

  1. Obtain a ticket for the administrator@AD.EXAMPLE.COM principal:
    ~]# kinit administrator@AD.EXAMPLE.COM
  2. Display the cached Kerberos ticket:
    ~]# klist
    Ticket cache: KEYRING:persistent:0:0
    Default principal: administrator@AD.EXAMPLE.COM
    
    Valid starting       Expires              Service principal
    11.09.2017 14:46:21  12.09.2017 00:46:21  krbtgt/AD.EXAMPLE.COM@AD.EXAMPLE.COM
    	renew until 18.09.2017 14:46:19

Listing the Available Domains

To list all domains available through the winbindd service, enter:
~]# wbinfo --all-domains
If Samba was successfully joined as a domain member, the command displays the built-in and local host name, as well as the domain Samba is a member of including trusted domains.

Example 15.2. Displaying the Available Domains

~]# wbinfo --all-domains
BUILTIN
SAMBA-SERVER
AD

15.1.5.3. Understanding ID Mapping

Windows domains distinguish users and groups by unique Security Identifiers (SID). However, Linux requires unique UIDs and GIDs for each user and group. If you run Samba as a domain member, the winbindd service is responsible for providing information about domain users and groups to the operating system.
To enable the winbindd service to provide unique IDs for users and groups to Linux, you must configure ID mapping in the /etc/samba/smb.conf file for:
  • The local database (default domain)
  • The AD or NT4 domain the Samba server is a member of
  • Each trusted domain from which users must be able to access resources on this Samba server
15.1.5.3.1. Planning ID Ranges
Regardless of whether you store the Linux UIDs and GIDs in AD or if you configure Samba to generate them, each domain configuration requires a unique ID range that must not overlap with any of the other domains.

Warning

If you set overlapping ID ranges, Samba fails to work correctly.

Example 15.3. Unique ID Ranges

The following shows non-overlapping ID mapping ranges for the default (*), AD-DOM, and the TRUST-DOM domains.
[global]
...
idmap config * : backend = tdb
idmap config * : range = 10000-999999

idmap config AD-DOM:backend = rid
idmap config AD-DOM:range = 2000000-2999999

idmap config TRUST-DOM:backend = rid
idmap config TRUST-DOM:range = 4000000-4999999

Important

You can only assign one range per domain. Therefore, leave enough space between the domains ranges. This enables you to extend the range later if your domain grows.
If you later assign a different range to a domain, the ownership of files and directories previously created by these users and groups will be lost.
15.1.5.3.2. The * Default Domain
In a domain environment, you add one ID mapping configuration for each of the following:
  • The domain the Samba server is a member of
  • Each trusted domain that should be able to access the Samba server
However, for all other objects, Samba assigns IDs from the default domain. This includes:
  • Local Samba users and groups
  • Samba built-in accounts and groups, such as BUILTIN\Administrators

Important

You must configure the default domain as described in this section to enable Samba to operate correctly.
The default domain back end must be writable to permanently store the assigned IDs.
For the default domain, you can use one of the following back ends:
tdb
When you configure the default domain to use the tdb back end, set an ID range that is big enough to include objects that will be created in the future and that are not part of a defined domain ID mapping configuration.
For example, set the following in the [global] section in the /etc/samba/smb.conf file:
idmap config * : backend = tdb
idmap config * : range = 10000-999999
autorid
When you configure the default domain to use the autorid back end, adding additional ID mapping configurations for domains is optional.
For example, set the following in the [global] section in the /etc/samba/smb.conf file:
idmap config * : backend = autorid
idmap config * : range = 10000-999999

15.1.5.4. The Different ID Mapping Back Ends

Samba provides different ID mapping back ends for specific configurations. The most frequently used back ends are:

Table 15.1. Frequently Used ID Mapping Back Ends

Back End Use Case
tdb The * default domain only
ad AD domains only
rid AD and NT4 domains
autorid AD, NT4, and the * default domain
The following sections describe the benefits, recommended scenarios where to use the back end, and how to configure it.
15.1.5.4.1. Using the tdb ID Mapping Back End
The winbindd service uses the writable tdb ID mapping back end by default to store Security Identifier (SID), UID, and GID mapping tables. This includes local users, groups, and built-in principals.
Use this back end only for the * default domain. For example:
idmap config * : backend = tdb
idmap config * : range = 10000-999999
For further details about the * default domain, see Section 15.1.5.3.2, “The * Default Domain”.
15.1.5.4.2. Using the ad ID Mapping Back End
The ad ID mapping back end implements a read-only API to read account and group information from AD. This provides the following benefits:
  • All user and group settings are stored centrally in AD.
  • User and group IDs are consistent on all Samba servers that use this back end.
  • The IDs are not stored in a local database which can corrupt, and therefore file ownerships cannot be lost.
The ad back end reads the following attributes from AD:

Table 15.2. Attributes the ad Back End Reads from User and Group Objects

AD Attribute Name Object Type Mapped to
sAMAccountName User and group User or group name, depending on the object
uidNumber User User ID (UID)
gidNumber Group Group ID (GID)
loginShell [a] User Path to the shell of the user
unixHomeDirectory [a] User Path to the home directory of the user
primaryGroupID [b] User Primary group ID
[a] Samba only reads this attribute if you set idmap config DOMAIN:unix_nss_info = yes.
[b] Samba only reads this attribute if you set idmap config DOMAIN:unix_primary_group = yes.
15.1.5.4.2.1. Prerequisites of the ad Back End
To use the ad ID mapping back end:
  • Both users and groups must have unique IDs set in AD, and the IDs must be within the range configured in the /etc/samba/smb.conf file. Objects whose IDs are outside of the range will not be available on the Samba server.
  • Users and groups must have all required attributes set in AD. If required attributes are missing, the user or group will not be available on the Samba server. The required attributes depend on your configuration. See Table 15.2, “Attributes the ad Back End Reads from User and Group Objects”.
15.1.5.4.2.2. Configuring the ad Back End
To configure a Samba AD member to use the ad ID mapping back end:

Procedure 15.5. Configuring the ad Back End on a Domain Member

  1. Edit the [global] section in the /etc/samba/smb.conf file:
    1. Add an ID mapping configuration for the default domain (*) if it does not exist. For example:
      idmap config * : backend = tdb
      idmap config * : range = 10000-999999
      For further details about the default domain configuration, see Section 15.1.5.3.2, “The * Default Domain”.
    2. Enable the ad ID mapping back end for the AD domain:
      idmap config DOMAIN : backend = ad
    3. Set the range of IDs that is assigned to users and groups in the AD domain. For example:
      idmap config DOMAIN : range = 2000000-2999999

      Important

      The range must not overlap with any other domain configuration on this server. Additionally, the range must be set big enough to include all IDs assigned in the future. For further details, see Section 15.1.5.3.1, “Planning ID Ranges”.
    4. Set that Samba uses the RFC 2307 schema when reading attributes from AD:
      idmap config DOMAIN : schema_mode = rfc2307
    5. To enable Samba to read the login shell and the path to the users home directory from the corresponding AD attribute, set:
      idmap config DOMAIN : unix_nss_info = yes
      Alternatively, you can set a uniform domain-wide home directory path and login shell that is applied to all users. For example:
      template shell = /bin/bash
      template homedir = /home/%U
      For details about variable substitution, see the VARIABLE SUBSTITUTIONS section in the smb.conf(5) man page.
    6. By default, Samba uses the primaryGroupID attribute of a user object as the user's primary group on Linux. Alternatively, you can configure Samba to use the value set in the gidNumber attribute instead:
      idmap config DOMAIN : unix_primary_group = yes
  2. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  3. Reload the Samba configuration:
    ~]# smbcontrol all reload-config
For further details, see the smb.conf(5) and idmap_ad(8) man pages.
15.1.5.4.3. Using the rid ID Mapping Back End
Samba can use the relative identifier (RID) of a Windows SID to generate an ID on Red Hat Enterprise Linux.

Note

The RID is the last part of a SID. For example, if the SID of a user is S-1-5-21-5421822485-1151247151-421485315-30014, then 30014 is the corresponding RID. For details, how Samba calculates the local ID, see the idmap_rid(8) man page.
The rid ID mapping back end implements a read-only API to calculate account and group information based on an algorithmic mapping scheme for AD and NT4 domains. When you configure the back end, you must set the lowest and highest RID in the idmap config DOMAIN : range parameter. Samba will not map users or groups with a lower or higher RID than set in this parameter.

Important

As a read-only back end, rid cannot assign new IDs, such as for BUILTIN groups. Therefore, do not use this back end for the * default domain.
15.1.5.4.3.1. Benefits and Drawbacks of Using the rid Back End

Benefits

  • All domain users and groups that have an RID within the configured range are automatically available on the domain member.
  • You do not need to manually assign IDs, home directories, and login shells.

Drawbacks

  • All domain users get the same login shell and home directory assigned. However, you can use variables.
  • User and group IDs are only the same across Samba domain members if all use the rid back end with the same ID range settings.
  • You cannot exclude individual users or groups from being available on the domain member. Only users and groups outside of the configured range are excluded.
  • Based on the formulas the winbindd service uses to calculate the IDs, duplicate IDs can occur in multi-domain environments if objects in different domains have the same RID.
15.1.5.4.3.2. Configuring the rid Back End
To configure a Samba domain member to use the rid ID mapping back end:

Procedure 15.6. Configuring the rid Back End on a Domain Member

  1. Edit the [global] section in the /etc/samba/smb.conf file:
    1. Add an ID mapping configuration for the default domain (*) if it does not exist. For example:
      idmap config * : backend = tdb
      idmap config * : range = 10000-999999
      For further details about the default domain configuration, see Section 15.1.5.3.2, “The * Default Domain”.
    2. Enable the rid ID mapping back end for the domain:
      idmap config DOMAIN : backend = rid
    3. Set a range that is big enough to include all RIDs that will be assigned in the future. For example:
      idmap config DOMAIN : range = 2000000-2999999
      Samba ignores users and groups whose RIDs in this domain are not within the range.

      Important

      The range must not overlap with any other domain configuration on this server. For further details, see Section 15.1.5.3.1, “Planning ID Ranges”.
    4. Set a shell and home directory path that will be assigned to all mapped users. For example:
      template shell = /bin/bash
      template homedir = /home/%U
      For details about variable substitution, see the VARIABLE SUBSTITUTIONS section in the smb.conf(5) man page.
  2. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  3. Reload the Samba configuration:
    ~]# smbcontrol all reload-config
15.1.5.4.4. Using the autorid ID Mapping Back End [2]
The autorid back end works similar to the rid ID mapping back end, but can automatically assign IDs for different domains. This enables you to use the autorid back end in the following situations:
  • Only for the * default domain.
  • For the * default domain and additional domains, without the need to create ID mapping configurations for each of the additional domains.
  • Only for specific domains.
15.1.5.4.4.1. Benefits and Drawbacks of Using the autorid Back End

Benefits

  • All domain users and groups whose calculated UID and GID is within the configured range are automatically available on the domain member.
  • You do not need to manually assign IDs, home directories, and login shells.
  • No duplicate IDs, even if multiple objects in a multi-domain environment have the same RID.

Drawbacks

  • User and group IDs are not the same across Samba domain members.
  • All domain users get the same login shell and home directory assigned. However, you can use variables.
  • You cannot exclude individual users or groups from being available on the domain member. Only users and groups whose calculated UID or GID is outside of the configured range are excluded.
15.1.5.4.4.2. Configuring the autorid Back End
To configure a Samba domain member to use the autorid ID mapping back end for the * default domain:

Note

If you use autorid for the default domain, adding additional ID mapping configuration for domains is optional.

Procedure 15.7. Configuring the autorid Back End on a Domain Member

  1. Edit the [global] section in the /etc/samba/smb.conf file:
    1. Enable the autorid ID mapping back end for the * default domain:
      idmap config * : backend = autorid
    2. Set a range that is big enough to assign IDs for all existing and future objects. For example:
      idmap config * : range = 10000-999999
      Samba ignores users and groups whose calculated IDs in this domain are not within the range. For details about how the back end calculated IDs, see the THE MAPPING FORMULAS section in the idmap_autorid(8) man page.

      Warning

      After you set the range and Samba starts using it, you can only increase the upper limit of the range. Any other change to the range can result in new ID assignments, and thus in loosing file ownerships.
    3. Optionally, set a range size. For example:
      idmap config * : rangesize = 200000
      Samba assigns this number of continuous IDs for each domain's object until all IDs from the range set in the idmap config * : range parameter are taken. For further details, see the rangesize parameter description in the idmap_autorid(8) man page.
    4. Set a shell and home directory path that will be assigned to all mapped users. For example:
      template shell = /bin/bash
      template homedir = /home/%U
      For details about variable substitution, see the VARIABLE SUBSTITUTIONS section in the smb.conf(5) man page.
    5. Optionally, add additional ID mapping configuration for domains. If no configuration for an individual domain is available, Samba calculates the ID using the autorid back end settings in the previously configured * default domain.

      Important

      If you configure additional back ends for individual domains, the ranges for all ID mapping configuration must not overlap. For further details, see Section 15.1.5.3.1, “Planning ID Ranges”.
  2. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  3. Reload the Samba configuration:
    ~]# smbcontrol all reload-config

15.1.6. Integrating a Samba File Server Into an IdM Domain

If you run Red Hat Identity Management (IdM) and Samba in your environment, you can configure the Samba server to authenticate IdM users using Kerberos when they access a share.
For details, see the corresponding section in the Red Hat Windows Integration Guide.

15.1.7. Configuring File Shares on a Samba Server

To use Samba as a file server, add shares to the /etc/samba/smb.conf file of your standalone or domain member configuration.
You can add shares that uses either:

15.1.7.1. Setting up a Share That Uses POSIX ACLs [3]

As a Linux service, Samba supports shares with POSIX ACLs. They enable you to manage permissions locally on the Samba server using utilities, such as chmod. If the share is stored on a file system that supports extended attributes, you can define ACLs with multiple users and groups.

Note

If you need to use fine-granular Windows ACLs instead, see Section 15.1.7.2, “Setting up a Share That Uses Windows ACLs ”.
Before you can add a share, set up Samba. See:
15.1.7.1.1. Adding a Share That Uses POSIX ACLs
To create a share named example, that provides the content of the /srv/samba/example/ directory, and uses POSIX ACLs:

Procedure 15.8. Adding a Share That Uses POSIX ACLs

  1. Optionally, create the folder if it does not exist. For example:
    ~]# mkdir -p /srv/samba/example/
  2. If you run SELinux in enforcing mode, set the samba_share_t context on the directory:
    ~]# semanage fcontext -a -t samba_share_t "/srv/samba/example(/.*)?"
    ~]# restorecon -Rv /srv/samba/example/
  3. Set file system ACLs on the directory. For details, see Section 15.1.7.1.2, “Setting ACLs”.
  4. Add the example share to the /etc/samba/smb.conf file. For example, to add the share write-enabled:
    [example]
    	path = /srv/samba/example/
    	read only = no

    Note

    Regardless of the file system ACLs; if you do not set read only = no, Samba shares the directory in read-only mode.
  5. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  6. Open the required ports and reload the firewall configuration using the firewall-cmd utility:
    ~]# firewall-cmd --permanent --add-service=samba
    ~]# firewall-cmd --reload
  7. Restart the smb service:
    ~]# systemctl restart smb
  8. Optionally, enable the smb service to start automatically at boot time:
    ~]# systemctl enable smb
15.1.7.1.2. Setting ACLs
Shares that use POSIX ACLs support:
15.1.7.1.2.1. Setting Standard Linux ACLs
The standard ACLs on Linux support setting permissions for one owner, one group, and for all other undefined users. You can use the chown, chgrp, and chmod utility to update the ACLs. If you require precise control, then you use the more complex POSIX ACLs, see Section 15.1.7.1.2.2, “Setting Extended ACLs”.
For example, to set the owner of the /srv/samba/example/ directory to the root user, grant read and write permissions to the Domain Users group, and deny access to all other users:
~]# chown root:"Domain Users" /srv/samba/example/
~]# chmod 2770 /srv/samba/example/

Note

Enabling the set-group-ID (SGID) bit on a directory automatically sets the default group for all new files and subdirectories to that of the directory group, instead of the usual behavior of setting it to the primary group of the user who created the new directory entry.
For further details about permissions, see the chown(1) and chmod(1) man pages.
15.1.7.1.2.2. Setting Extended ACLs
If the file system the shared directory is stored on supports extended ACLs, you can use them to set complex permissions. Extended ACLs can contain permissions for multiple users and groups.
Extended POSIX ACLs enable you to to configure complex ACLs with multiple users and groups. However, you can only set the following permissions:
  • No access
  • Read access
  • Write access
  • Full control
If you require the fine-granular Windows permissions, such as Create folder / append data, configure the share to use Windows ACLs. See Section 15.1.7.2, “Setting up a Share That Uses Windows ACLs ”.
To use extended POSIX ACLs on a share:

Procedure 15.9. Enabling Extended POSIX ACLs on a Share

  1. Enable the following parameter in the share's section in the /etc/samba/smb.conf file to enable ACL inheritance of extended ACLs:
    inherit acls = yes
    For details, see the parameter description in the smb.conf(5) man page.
  2. Restart the smb service:
    ~]# systemctl restart smb
  3. Optionally, enable the smb service to start automatically at boot time:
    ~]# systemctl enable smb
  4. Set the ACLs on the directory. For details about using extended ACLs, see Chapter 4, Access Control Lists.

    Example 15.4. Setting Extended ACLs

    The following procedure sets read, write, and execute permissions for the Domain Admins group, read, and execute permissions for the Domain Users group, and deny access to everyone else on the /srv/samba/example/ directory:

    Procedure 15.10. Setting Extended ACLs

    1. Disable auto-granting permissions to the primary group of user accounts:
      ~]# setfacl -m group::--- /srv/samba/example/
      ~]# setfacl -m default:group::--- /srv/samba/example/
      The primary group of the directory is additionally mapped to the dynamic CREATOR GROUP principal. When you use extended POSIX ACLs on a Samba share, this principal is automatically added and you cannot remove it.
    2. Set the permissions on the directory:
      1. Grant read, write, and execute permissions to the Domain Admins group:
        ~]# setfacl -m group:"DOMAIN\Domain Admins":rwx /srv/samba/example/
      2. Grant read and execute permissions to the Domain Users group:
        ~]# setfacl -m group:"DOMAIN\Domain Users":r-x /srv/samba/example/
      3. Set permissions for the other ACL entry to deny access to users that do not match the other ACL entries:
        ~]# setfacl -R -m other::--- /srv/samba/example/
      These settings apply only to this directory. In Windows, these ACLs are mapped to the This folder only mode.
    3. To enable the permissions set in the previous step to be inherited by new file system objects created in this directory:
      ~]# setfacl -m default:group:"DOMAIN\Domain Admins":rwx /srv/samba/example/
      ~]# setfacl -m default:group:"DOMAIN\Domain Users":r-x /srv/samba/example/
      ~]# setfacl -m default:other::--- /srv/samba/example/
      With these settings, the This folder only mode for the principals is now set to This folder, subfolders, and files.
    Samba maps the previously set permissions to the following Windows ACLs:
    Principal Access Applies to
    DOMAIN\Domain Admins Full control This folder, subfolders, and files
    DOMAIN\Domain Users Read & execute This folder, subfolders, and files
    Everyone [a] None This folder, subfolders, and files
    owner (Unix User\owner) [b] Full control This folder only
    primary_group (Unix User\primary_group) [c] None This folder only
    CREATOR OWNER [d] [e] Full control Subfolders and files only
    CREATOR GROUP [f] [e] None Subfolders and files only
    [a] Samba maps the permissions for this principal from the other ACL entry.
    [b] Samba maps the owner of the directory to this entry.
    [c] Samba maps the primary group of the directory to this entry.
    [d] On new file system objects, the creator inherits automatically the permissions of this principal.
    [e] Configuring or removing these principals from the ACLs not supported on shares that use POSIX ACLs.
    [f] On new file system objects, the creator's primary group inherits automatically the permissions of this principal.
15.1.7.1.3. Setting Permissions on a Share
Optionally, to limit or grant access to a Samba share, you can set certain parameters in the share's section in the /etc/samba/smb.conf file.

Note

Share-based permissions manage if a user, group, or host is able to access a share. These settings do not affect file system ACLs.
Use share-based settings to restrict access to shares. For example, to deny access from specific hosts.
15.1.7.1.3.1. Configuring User and Group-based Share Access
User and group-based access control enables you to grant or deny access to a share for certain users and groups. For example, to enable all members of the Domain Users group to access a share while access is denied for the user account, add the following parameters to the share's configuration:
valid users = +DOMAIN\"Domain Users"
invalid users = DOMAIN\user
The invalid users parameter has a higher priority than valid users parameter. For example, if the user account is a member of the Domain Users group, access is denied to this account when you use the previous example.
For further details, see the parameter descriptions in the smb.conf(5) man page.
15.1.7.1.3.2. Configuring Host-based Share Access
Host-based access control enables you to grant or deny access to a share based on client's host names, IP addresses, or IP ranges.
For example, to enable the 127.0.0.1 IP address, the 192.0.2.0/24 IP range, and the client1.example.com host to access a share, and additionally deny access for the client2.example.com host:

Procedure 15.11. Configuring Host-based Share Access

  1. Add the following parameters to the configuration of the share in the /etc/samba/smb.conf:
    hosts allow = 127.0.0.1 192.0.2.0/24 client1.example.com
    hosts deny = client2.example.com
  2. Reload the Samba configuration
    ~]# smbcontrol all reload-config
The hosts deny parameter has a higher priority than hosts allow. For example, if client1.example.com resolves to an IP address that is listed in the hosts allow parameter, access for this host is denied.
For further details, see the parameter description in the smb.conf(5) man page.

15.1.7.2. Setting up a Share That Uses Windows ACLs [4]

Samba supports setting Windows ACLs on shares and file system object. This enables you to:
  • Use the fine-granular Windows ACLs
  • Manage share permissions and file system ACLs using Windows
Alternatively, you can configure a share to use POSIX ACLs. For details, see Section 15.1.7.1, “Setting up a Share That Uses POSIX ACLs ”.
15.1.7.2.1. Granting the SeDiskOperatorPrivilege Privilege
Only users and groups having the SeDiskOperatorPrivilege privilege granted can configure permissions on shares that use Windows ACLs. For example, to grant the privilege to the DOMAIN\Domain Admins group:
~]# net rpc rights grant "DOMAIN\Domain Admins" SeDiskOperatorPrivilege \
       -U "DOMAIN\administrator"
Enter DOMAIN\administrator's password:
Successfully granted rights.

Note

In a domain environment, grant SeDiskOperatorPrivilege to a domain group. This enables you to centrally manage the privilege by updating a user's group membership.
To list all users and groups having SeDiskOperatorPrivilege granted:
~]# net rpc rights list privileges SeDiskOperatorPrivilege \
       -U "DOMAIN\administrator"
Enter administrator's password:
SeDiskOperatorPrivilege:
  BUILTIN\Administrators
  DOMAIN\Domain Admins
15.1.7.2.2. Enabling Windows ACL Support
To configure shares that support Windows ACLs, you must enable this feature in Samba. To enable it globally for all shares, add the following settings to the [global] section of the /etc/samba/smb.conf file:
vfs objects = acl_xattr
map acl inherit = yes
store dos attributes = yes
Alternatively, you can enable Windows ACL support for individual shares, by adding the same parameters to a share's section instead.
15.1.7.2.3. Adding a Share That Uses Windows ACLs
To create a share named example, that shares the content of the /srv/samba/example/ directory, and uses Windows ACLs:

Procedure 15.12. Adding a Share That Uses Windows ACLs

  1. Optionally, create the folder if it does not exists. For example:
    ~]# mkdir -p /srv/samba/example/
  2. If you run SELinux in enforcing mode, set the samba_share_t context on the directory:
    ~]# semanage fcontext -a -t samba_share_t "/srv/samba/example(/.*)?"
    ~]# restorecon -Rv /srv/samba/example/
  3. Add the example share to the /etc/samba/smb.conf file. For example, to add the share write-enabled:
    [example]
    	path = /srv/samba/example/
    	read only = no

    Note

    Regardless of the file system ACLs; if you do not set read only = no, Samba shares the directory in read-only mode.
  4. If you have not enabled Windows ACL support in the [global] section for all shares, add the following parameters to the [example] section to enable this feature for this share:
    vfs objects = acl_xattr
    map acl inherit = yes
    store dos attributes = yes
  5. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  6. Open the required ports and reload the firewall configuration using the firewall-cmd utility:
    ~]# firewall-cmd --permanent --add-service=samba
    ~]# firewall-cmd --reload
  7. Restart the smb service:
    ~]# systemctl restart smb
  8. Optionally, enable the smb service to start automatically at boot time:
    ~]# systemctl enable smb
15.1.7.2.4. Managing Share Permissions and File System ACLs of a Share That Uses Windows ACLs
To manage share and file system ACLs on a Samba share that uses Windows ACLs, use a Windows applications, such as Computer Management. For details, see your Windows documentation.
Alternatively, use the smbcacls utility to manage ACLs. For details, see Section 15.1.7.3, “Managing ACLs on an SMB Share Using smbcacls.

Note

To modify the file system permissions from Windows, you must use an account that has the SeDiskOperatorPrivilege privilege granted. See Section 15.1.7.2.1, “Granting the SeDiskOperatorPrivilege Privilege”.

15.1.7.3. Managing ACLs on an SMB Share Using smbcacls

The smbcacls utility can list, set, and delete ACLs of files and directories stored on an SMB share. You can use smbcacls to manage file system ACLs:
  • On a local or remote Samba server that uses advanced Windows ACLs or POSIX ACLs.
  • On Red Hat Enterprise Linux to remotely manage ACLs on a share hosted on Windows.
15.1.7.3.1. Understanding Access Control Entries
Each ACL entry of a file system object contains Access Control Entries (ACE) in the following format:
security_principal:access_right/inheritance_information/permissions

Example 15.5. Access Control Entries

If the AD\Domain Users group has Modify permissions that apply to This folder, subfolders, and files on Windows, the ACL contains the following ACEs:
AD\Domain Users:ALLOWED/OI|CI/CHANGE
The following describes the individual ACEs:
Security principal
The security principal is the user, group, or SID the permissions in the ACL are applied to.
Access right
Defines if access to an object is granted or denied. The value can be ALLOWED or DENIED.
Inheritance information
The following values exist:

Table 15.3. Inheritance Settings

Value Description Maps to
OI Object Inherit This folder and files
CI Container Inherit This folder and subfolders
IO Inherit Only The ACE does not apply to the current file or directory.
ID Inherited The ACE was inherited from the parent directory.
Additionally, the values can be combined as follows:

Table 15.4. Inheritance Settings Combinations

Value Combinations Maps to the Windows Applies to Setting
OI|CI This folder, subfolders, and files
OI|CI|IO Subfolders and files only
CI|IO Subfolders only
OI|IO Files only
Permissions
This value can be either a hex value that represents one or more Windows permissions or an smbcacls alias:
  • A hex value that represents one or more Windows permissions.
    The following table displays the advanced Windows permissions and their corresponding value in hex format:

    Table 15.5. Windows Permissions and Their Corresponding smbcacls Value in Hex Format

    Windows Permissions Hex Values
    Full control 0x001F01FF
    Traverse folder / execute file 0x00100020
    List folder / read data 0x00100001
    Read attributes 0x00100080
    Read extended attributes 0x00100008
    Create files / write data 0x00100002
    Create folders / append data 0x00100004
    Write attributes 0x00100100
    Write extended attributes 0x00100010
    Delete subfolders and files 0x00100040
    Delete 0x00110000
    Read permissions 0x00120000
    Change permissions 0x00140000
    Take ownership 0x00180000
    Multiple permissions can be combined as a single hex value using the bit-wise OR operation. For details, see Section 15.1.7.3.3, “Calculating an ACE Mask”.
  • An smbcacls alias. The following table displays the available aliases:

    Table 15.6. Existing smbcacls Aliases and Their Corresponding Windows Permission

    smbcacls Alias Maps to Windows Permission
    R Read
    READ Read & execute
    W
    Special
    • Create files / write data
    • Create folders / append data
    • Write attributes
    • Write extended attributes
    • Read permissions
    D Delete
    P Change permissions
    O Take ownership
    X Traverse / execute
    CHANGE Modify
    FULL Full control

    Note

    You can combine single-letter aliases when you set permissions. For example, you can set RD to apply the Windows permission Read and Delete. However, you can neither combine multiple non-single-letter aliases nor combine aliases and hex values.
15.1.7.3.2. Displaying ACLs Using smbcacls
If you run smbcacls without any operation parameter, such as --add, the utility displays the ACLs of a file system object.
For example, to list the ACLs of the root directory of the //server/example share:
~]# smbcacls //server/example / -U "DOMAIN\administrator"
Enter DOMAIN\administrator's password:
REVISION:1
CONTROL:SR|PD|DI|DP
OWNER:AD\Administrators
GROUP:AD\Domain Users
ACL:AD\Administrator:ALLOWED/OI|CI/FULL
ACL:AD\Domain Users:ALLOWED/OI|CI/CHANGE
ACL:AD\Domain Guests:ALLOWED/OI|CI/0x00100021
The output of the command displays:
  • REVISION: The internal Windows NT ACL revision of the security descriptor
  • CONTROL: Security descriptor control
  • OWNER: Name or SID of the security descriptor's owner
  • GROUP: Name or SID of the security descriptor's group
15.1.7.3.3. Calculating an ACE Mask
In most situations, when you add or update an ACE, you use the smbcacls aliases listed in Table 15.6, “Existing smbcacls Aliases and Their Corresponding Windows Permission”.
However, if you want to set advanced Windows permissions as listed in Table 15.5, “Windows Permissions and Their Corresponding smbcacls Value in Hex Format”, you must use the bit-wise OR operation to calculate the correct value. You can use the following shell command to calculate the value:
~]# echo $(printf '0x%X' $(( hex_value_1 | hex_value_2 | ... )))

Example 15.6. Calculating an ACE Mask

You want set following permissions:
  • Traverse folder / execute file (0x00100020)
  • List folder / read data (0x00100001)
  • Read attributes (0x00100080)
To calculate the hex value for the previous permissions, enter:
~]# echo $(printf '0x%X' $(( 0x00100020 | 0x00100001 | 0x00100080 )))
0x1000A1
Use the returned value when you set or update an ACE.
15.1.7.3.4. Adding, Updating, And Removing an ACL Using smbcacls
Depending on the parameter you pass to the smbcacls utility, you can add, update, and remove ACLs from a file or directory.

Adding an ACL

To add an ACL to the root of the //server/example share that grants CHANGE permissions for This folder, subfolders, and files to the AD\Domain Users group:
~]# smbcacls //server/example / -U "DOMAIN\administrator \
       --add ACL:"AD\Domain Users":ALLOWED/OI|CI/CHANGE

Updating an ACL

Updating an ACL is similar to adding a new ACL. You update an ACL by overriding the ACL using the --modify parameter with an existing security principal. If smbcacls finds the security principal in the ACL list, the utility updates the permissions. Otherwise the command fails with an error:
ACL for SID principal_name not found
For example, to update the permissions of the AD\Domain Users group and set them to READ for This folder, subfolders, and files:
~]# smbcacls //server/example / -U "DOMAIN\administrator \
       --modify ACL:"AD\Domain Users":ALLOWED/OI|CI/READ

Deleting an ACL

To delete an ACL, pass the --delete with the exact ACL to the smbcacls utility. For example:
~]# smbcacls //server/example / -U "DOMAIN\administrator \
       --delete ACL:"AD\Domain Users":ALLOWED/OI|CI/READ

15.1.7.4. Enabling Users to Share Directories on a Samba Server

On a Samba server, you can configure that users can share directories without root permissions.
15.1.7.4.1. Enabling the User Shares Feature
Before users can share directories, the administrator must enable user shares in Samba. For example, to enable only members of the local example group to create user shares:

Procedure 15.13. Enabling User Shares

  1. Create the local example group, if it does not exist:
    ~]# groupadd example
  2. Prepare the directory for Samba to store the user share definitions and set its permissions properly. For example:
    1. Create the directory:
      ~]# mkdir -p /var/lib/samba/usershares/
    2. Set write permissions for the example group:
      ~]# chgrp example /var/lib/samba/usershares/
      ~]# chmod 1770 /var/lib/samba/usershares/
      Set the sticky bit to prevent users to rename or delete files stored by other users in this directory.
  3. Edit the /etc/samba/smb.conf file and add the following to the [global] section:
    1. Set the path to the directory you configured to store the user share definitions. For example:
      usershare path = /var/lib/samba/usershares/
    2. Set how many user shares Samba allows to be created on this server. For example:
      usershare max shares = 100
      If you use the default of 0 for the usershare max shares parameter, user shares are disabled.
    3. Optionally, set a list of absolute directory paths. For example, to configure that Samba only allows to share subdirectories of the /data and /srv directory to be shared, set:
      usershare prefix allow list = /data /srv
    For a list of further user share-related parameters you can set, see the USERSHARES section in the smb.conf(5) man page.
  4. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  5. Reload the Samba configuration:
    ~]# smbcontrol all reload-config
Users are now able to create user shares. For details, see Section 15.1.7.4.2, “Adding a User Share”.
15.1.7.4.2. Adding a User Share
After you configured Samba according to Section 15.1.7.4.1, “Enabling the User Shares Feature”, users can share directories on the Samba server without root permissions by running the net usershare add command.
Synopsis of the net usershare add command:

net usershare add share_name path [[ comment ] | [ ACLs ]] [ guest_ok=y|n ]

Important

If you set ACLs when you create a user share, you must specify the comment parameter prior to the ACLs. To set an empty comment, use an empty string in double quotes.
Note that users can only enable guest access on a user share, if the administrator set usershare allow guests = yes in the [global] section in the /etc/samba/smb.conf file.

Example 15.7. Adding a User Share

A user wants to share the /srv/samba/ directory on a Samba server. The share should be named example, have no comment set, and should be accessible by guest users. Additionally, the share permissions should be set to full access for the AD\Domain Users group and read permissions for other users. To add this share, run as the user:
~]$ net usershare add example /srv/samba/ "" \
       "AD\Domain Users":F,Everyone:R guest_ok=yes
15.1.7.4.3. Updating Settings of a User Share
If you want to update settings of a user share, override the share by using the net usershare add command with the same share name and the new settings. See Section 15.1.7.4.2, “Adding a User Share”.
15.1.7.4.4. Displaying Information About Existing User Shares
Users can enter the net usershare info command on a Samba server to display user shares and their settings.
To display all user shares created by any user:
~]$ net usershare info -l
[share_1]
path=/srv/samba/
comment=
usershare_acl=Everyone:R,host_name\user:F,
guest_ok=y
...
To list only shares created by the user who runs the command, omit the -l parameter.
To display only the information about specific shares, pass the share name or wild cards to the command. For example, to display the information about shares whose name starts with share_:
~]$ net usershare info -l share_*
15.1.7.4.5. Listing User Shares
If you want to list only the available user shares without their settings on a Samba server, use the net usershare list command.
To list the shares created by any user:
~]$ net usershare list -l
share_1
share_2
...
To list only shares created by the user who runs the command, omit the -l parameter.
To list only specific shares, pass the share name or wild cards to the command. For example, to list only shares whose name starts with share_:
~]$ net usershare list -l share_*
15.1.7.4.6. Deleting a User Share
To delete a user share, enter as the user who created the share or as the root user:
~]$ net usershare delete share_name

15.1.7.5. Enabling Guest Access to a Share

In certain situations, you want to share a directory to which users can connect without authentication. To configure this, enable guest access on a share.

Warning

Shares that do not require authentication can be a security risk.
If guest access is enabled on a share, Samba maps guest connections to the operating system account set in the guest account parameter. Guest users can access these files if at least one of the following conditions is satisfied:
  • The account is listed in file system ACLs
  • The POSIX permissions for other users allow it

Example 15.8. Guest Share Permissions

If you configured Samba to map the guest account to nobody, which is the default, the ACLs in the following example:
  • Allow guest users to read file1.txt
  • Allow guest users to read and modify file2.txt.
  • Prevent guest users to read or modify file3.txt
-rw-r--r--. 1 root       root      1024 1. Sep 10:00 file1.txt
-rw-r-----. 1 nobody     root      1024 1. Sep 10:00 file2.txt
-rw-r-----. 1 root       root      1024 1. Sep 10:00 file3.txt
For example, to enable guest access for the existing [example] share:

Procedure 15.14. Setting up a Guest Share

  1. Edit the /etc/samba/smb.conf file:
    1. If this is the first guest share you set up on this server:
      1. Set map to guest = Bad User in the [global] section:
        [global]
        	...
        	map to guest = Bad User
        With this setting, Samba rejects login attempts that use an incorrect password unless the user name does not exist. If the specified user name does not exist and guest access is enabled on a share, Samba treats the connection as a guest log in.
      2. By default, Samba maps the guest account to the nobody account on Red Hat Enterprise Linux. Optionally, you can set a different account. For example:
        [global]
        	...
        	guest account = user_name
        The account set in this parameter must exist locally on the Samba server. For security reasons, Red Hat recommends using an account that does not have a valid shell assigned.
    2. Add the guest ok = yes setting to the [example] section:
      [example]
      	...
      	guest ok = yes
  2. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  3. Reload the Samba configuration:
    ~]# smbcontrol all reload-config

15.1.8. Setting up a Samba Print Server [5]

If you set up Samba as a print server, clients in your network can use Samba to print. Additionally, Windows clients can, if configured, download the driver from the Samba server.
Before you can share a printer, set up Samba:

15.1.8.1. The Samba spoolssd Service

The Samba spoolssd is a service that is integrated into the smbd service. Enable spoolssd in the Samba configuration to significantly increase the performance on print servers with a high number of jobs or printers.
Without spoolssd, Samba forks the smbd process and initializes the printcap cache for each print job. In case of a large number of printers, the smbd service can become unresponsive for multiple seconds while the cache is initialized. The spoolssd service enables you to start pre-forked smbd processes that are processing print jobs without any delays. The main spoolssd smbd process uses a low amount of memory, and forks and terminates child processes.
To enable the spoolssd service:

Procedure 15.15. Enabling the spoolssd Service

  1. Edit the [global] section in the /etc/samba/smb.conf file:
    1. Add the following parameters:
      rpc_server:spoolss = external
      rpc_daemon:spoolssd = fork
    2. Optionally, you can set the following parameters:
      Parameter Default Description
      spoolssd:prefork_min_children 5 Minimum number of child processes
      spoolssd:prefork_max_children 25 Maximum number of child processes
      spoolssd:prefork_spawn_rate 5 Samba forks the number of new child processes set in this parameter, up to the value set in spoolssd:prefork_max_children, if a new connection is established
      spoolssd:prefork_max_allowed_clients 100 Number of clients, a child process serves
      spoolssd:prefork_child_min_life 60 Minimum lifetime of a child process in seconds. 60 seconds is the minimum.
  2. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  3. Restart the smb service:
    ~]# systemctl restart smb
After you restarted the service, Samba automatically starts smbd child processes:
~]# ps axf
...
30903 smbd
30912  \_ smbd
30913      \_ smbd
30914      \_ smbd
30915      \_ smbd
...

15.1.8.2. Enabling Print Server Support in Samba

To enable the print server support:

Procedure 15.16. Enabling Print Server Support in Samba

  1. On the Samba server, set up CUPS and add the printer to the CUPS back end. For details, see Section 15.3, “Print Settings”.

    Note

    Samba can only forward the print jobs to CUPS if CUPS is installed locally on the Samba print server.
  2. Edit the /etc/samba/smb.conf file:
    1. If you want to enable the spoolssd service, add the following parameters to the [global] section:
      rpc_server:spoolss = external
      rpc_daemon:spoolssd = fork
    2. To configure the printing back end, add the [printers] section:
      [printers]
      	comment = All Printers
      	path = /var/tmp/
      	printable = yes
      	create mask = 0600

      Important

      The printers share name is hard-coded and cannot be changed.
  3. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  4. Open the required ports and reload the firewall configuration using the firewall-cmd utility:
    ~]# firewall-cmd --permanent --add-service=samba
    ~]# firewall-cmd --reload
  5. Restart the smb service:
    ~]# systemctl restart smb
After restarting the service, Samba automatically shares all printers that are configured in the CUPS back end. If you want to manually share only specific printers, see Section 15.1.8.3, “Manually Sharing Specific Printers”.

15.1.8.3. Manually Sharing Specific Printers

If you configured Samba as a print server, by default, Samba shares all printers that are configured in the CUPS back end. To share only specific printers:

Procedure 15.17. Manually Sharing a Specific Printer

  1. Edit the /etc/samba/smb.conf file:
    1. In the [global] section, disable automatic printer sharing by setting:
      load printers = no
    2. Add a section for each printer you want to share. For example, to share the printer named example in the CUPS back end as Example-Printer in Samba, add the following section:
      [Example-Printer]
      	path = /var/tmp/
      	printable = yes
      	printer name = example
      You do not need individual spool directories for each printer. You can set the same spool directory in the path parameter for the printer as you set in the [printers] section.
  2. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  3. Reload the Samba configuration:
    ~]# smbcontrol all reload-config

15.1.8.4. Setting up Automatic Printer Driver Downloads for Windows Clients [6]

If you are running a Samba print server for Windows clients, you can upload drivers and preconfigure printers. If a user connects to a printer, Windows automatically downloads and installs the driver locally on the client. The user does not require local administrator permissions for the installation. Additionally, Windows applies preconfigured driver settings, such as the number of trays.

Note

Before setting up automatic printer driver download, must configure Samba as a print server and share a printer. For details, see Section 15.1.8, “Setting up a Samba Print Server ”.
15.1.8.4.1. Basic Information about Printer Drivers
This section provides general information about printer drivers.

Supported Driver Model Version

Samba only supports the printer driver model version 3 which is supported in Windows 2000 and later, and Windows Server 2000 and later. Samba does not support the driver model version 4, introduced in Windows 8 and Windows Server 2012. However, these and later Windows versions also support version 3 drivers.

Package-aware Drivers

Samba does not support package-aware drivers.

Preparing a Printer Driver for Being Uploaded

Before you can upload a driver to a Samba print server:
  • Unpack the driver if it is provided in a compressed format.
  • Some drivers require to start a setup application that installs the driver locally on a Windows host. In certain situations, the installer extracts the individual files into the operating system's temporary folder during the setup runs. To use the driver files for uploading:
    1. Start the installer.
    2. Copy the files from the temporary folder to a new location.
    3. Cancel the installation.
Ask your printer manufacturer for drivers that support uploading to a print server.

Providing 32-bit and 64-bit Drivers for a Printer to a Client

To provide the driver for a printer for both 32-bit and 64-bit Windows clients, you must upload a driver with exactly the same name for both architectures. For example, if you are uploading the 32-bit driver named Example PostScript and the 64-bit driver named Example PostScript (v1.0), the names do not match. Consequently, you can only assign one of the drivers to a printer and the driver will not be available for both architectures.
15.1.8.4.2. Enabling Users to Upload and Preconfigure Drivers
To be able to upload and preconfigure printer drivers, a user or a group needs to have the SePrintOperatorPrivilege privilege granted. For example, to grant the privilege to the printadmin group:
~]# net rpc rights grant "printadmin" SePrintOperatorPrivilege \
       -U "DOMAIN\administrator"
Enter DOMAIN\administrator's password:
Successfully granted rights.

Note

In a domain environment, grant SePrintOperatorPrivilege to a domain group. This enables you to centrally manage the privilege by updating a user's group membership.
To list all users and groups having SePrintOperatorPrivilege granted:
~]# net rpc rights list privileges SePrintOperatorPrivilege \
       -U "DOMAIN\administrator"
Enter administrator's password:
SePrintOperatorPrivilege:
  BUILTIN\Administrators
  DOMAIN\printadmin
15.1.8.4.3. Setting up the print$ Share
Windows operating systems download printer drivers from a share named print$ from a print server. This share name is hard-coded in Windows and cannot be changed.
To share the /var/lib/samba/drivers/ directory as print$, and enable members of the local printadmin group to upload printer drivers:

Procedure 15.18. Setting up the print$ Share

  1. Add the [print$] section to the /etc/samba/smb.conf file:
    [print$]
    	path = /var/lib/samba/drivers/
    	read only = no
    	write list = @printadmin
    	force group = @printadmin
    	create mask = 0664
    	directory mask = 2775
    Using these settings:
    • Only members of the printadmin group can upload printer drivers to the share.
    • The group of new created files and directories will be set to printadmin.
    • The permissions of new files will be set to 664.
    • The permissions of new directories will be set to 2775.
  2. To upload only 64-bit drivers for a printer, include this setting in the [global] section in the /etc/samba/smb.conf file:
    spoolss: architecture = Windows x64
    Without this setting, Windows only displays drivers for which you have uploaded at least the 32-bit version.
  3. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  4. Reload the Samba configuration
    ~]# smbcontrol all reload-config
  5. Create the printadmin group if it does not exists:
    ~]# groupadd printadmin
  6. Grant the SePrintOperatorPrivilege privilege to the printadmin group.
    ~]# net rpc rights grant "printadmin" SePrintOperatorPrivilege \
           -U "DOMAIN\administrator"
    Enter DOMAIN\administrator's password:
    Successfully granted rights.
  7. If you run SELinux in enforcing mode, set the samba_share_t context on the directory:
    ~]# semanage fcontext -a -t samba_share_t "/var/lib/samba/drivers(/.*)?"
    ~]# restorecon -Rv /var/lib/samba/drivers/
  8. Set the permissions on the /var/lib/samba/drivers/ directory:
    • If you use POSIX ACLs, set:
      ~]# chgrp -R "printadmin" /var/lib/samba/drivers/
      ~]# chmod -R 2775 /var/lib/samba/drivers/
    • If you use Windows ACLs, set:
      Principal Access Apply to
      CREATOR OWNER Full control Subfolders and files only
      Authenticated Users Read & execute, List folder contents, Read This folder, subfolders and files
      printadmin Full control This folder, subfolders and files
      For details about setting ACLs on Windows, see your Windows documentation.
15.1.8.4.4. Creating a GPO to Enable Clients to Trust the Samba Print Server
For security reasons, recent Windows operating systems prevent clients from downloading non-package-aware printer drivers from an untrusted server. If your print server is a member in an AD, you can create a Group Policy Object (GPO) in your domain to trust the Samba server.
To create GPOs, the Windows computer you are using must have the Windows Remote Server Administration Tools (RSAT) installed. For details, see your Windows documentation.

Procedure 15.19. Creating a GPO to Enable Clients to Trust the Samba Print Server

  1. Log into a Windows computer using an account that is allowed to edit group policies, such as the AD domain Administrator user.
  2. Open the Group Policy Management Console.
  3. Right-click to your AD domain and select Create a GPO in this domain, and Link it here
  4. Enter a name for the GPO, such as Legacy printer Driver Policy and click OK. The new GPO will be displayed under the domain entry.
  5. Right-click to the newly-created GPO and select Edit to open the Group Policy Management Editor.
  6. Navigate to Computer ConfigurationPoliciesAdministrative TemplatesPrinters.
  7. On the right side of the window, double-click Point and Print Restriction to edit the policy:
    1. Enable the policy and set the following options:
      1. Select Users can only point and print to these servers and enter the fully-qualified domain name (FQDN) of the Samba print server to the field next to this option.
      2. In both check boxes under Security Prompts, select Do not show warning or elevation prompt.
    2. Click OK.
  8. Double-click Package Point and Print - Approved servers to edit the policy:
    1. Enable the policy and click the Show button.
    2. Enter the FQDN of the Samba print server.
    3. Close both the Show Contents and policy properties window by clicking OK.
  9. Close the Group Policy Management Editor.
  10. Close the Group Policy Management Console.
After the Windows domain members applied the group policy, printer drivers are automatically downloaded from the Samba server when a user connects to a printer.
For further details about using group policies, see your Windows documentation.
15.1.8.4.5. Uploading Drivers and Preconfiguring Printers
Use the Print Management application on a Windows client to upload drivers and preconfigure printers hosted on the Samba print server. For further details, see your Windows documentation.

15.1.9. Tuning the Performance of a Samba Server [7]

This section describes what settings can improve the performance of Samba in certain situations, and which settings can have a negative performance impact.

15.1.9.1. Setting the SMB Protocol Version

Each new SMB version adds features and improves the performance of the protocol. The recent Windows and Windows Server operating systems always supports the latest protocol version. If Samba also uses the latest protocol version, Windows clients connecting to Samba benefit from the performance improvements. In Samba, the default value of the server max protocol is set to the latest supported stable SMB protocol version.
To always have the latest stable SMB protocol version enabled, do not set the server max protocol parameter. If you set the parameter manually, you will need to modify the setting with each new version of the SMB protocol, to have the latest protocol version enabled.
To unset, remove the server max protocol parameter from the [global] section in the /etc/samba/smb.conf file.

15.1.9.2. Tuning Shares with Directories That Contain a Large Number of Files

To improve the performance of shares that contain directories with more than 100.000 files:

Procedure 15.20. Tuning Shares with Directories That Contain a Large Number of Files

  1. Rename all files on the share to lowercase.

    Note

    Using the settings in this procedure, files with names other than in lowercase will no longer be displayed.
  2. Set the following parameters in the share's section:
    case sensitive = true
    default case = lower
    preserve case = no
    short preserve case = no
    For details about the parameters, see their descriptions in the smb.conf(5) man page.
  3. Reload the Samba configuration:
    ~]# smbcontrol all reload-config
After you applied these settings, the names of all newly created files on this share use lowercase. Because of these settings, Samba no longer needs to scan the directory for uppercase and lowercase, which improves the performance.

15.1.9.3. Settings That Can Have a Negative Performance Impact

By default, the kernel in Red Hat Enterprise Linux is tuned for high network performance. For example, the kernel uses an auto-tuning mechanism for buffer sizes. Setting the socket options parameter in the /etc/samba/smb.conf file overrides these kernel settings. As a result, setting this parameter decreases the Samba network performance in most cases.
To use the optimized settings from the Kernel, remove the socket options parameter from the [global] section in the /etc/samba/smb.conf.

15.1.10. Frequently Used Samba Command-line Utilities

This section describes frequently used commands when working with a Samba server.

15.1.10.1. Using the net Utility

The net utility enables you to perform several administration tasks on a Samba server. This section describes the most frequently used subcommands of the net utility.
For further details, see the net(8) man page.
15.1.10.1.1. Using the net ads join and net rpc join Commands
Using the join subcommand of the net utility, you can join Samba to an AD or NT4 domain. To join the domain, you must create the /etc/samba/smb.conf file manually, and optionally update additional configurations, such as PAM.

Important

Red Hat recommends using the realm utility to join a domain. The realm utility automatically updates all involved configuration files. For details, see Section 15.1.5.1, “Joining a Domain”.
To join a domain using the net command:

Procedure 15.21. Joining a Domain Using the net Command

  1. Manually create the /etc/samba/smb.conf file with the following settings:
    • For an AD domain member:
      [global]
      workgroup = domain_name
      security = ads
      passdb backend = tdbsam
      realm = AD_REALM
    • For an NT4 domain member:
      [global]
      workgroup = domain_name
      security = user
      passdb backend = tdbsam
  2. Add an ID mapping configuration for the * default domain and for the domain you want to join to the [global] section in the /etc/samba/smb.conf. For details, see Section 15.1.5.3, “Understanding ID Mapping”.
  3. Verify the /etc/samba/smb.conf file:
    ~]# testparm
  4. Join the domain as the domain administrator:
    • To join an AD domain:
      ~]# net ads join -U "DOMAIN\administrator"
    • To join an NT4 domain:
      ~]# net rpc join -U "DOMAIN\administrator"
  5. Append the winbind source to the passwd and group database entry in the /etc/nsswitch.conf file:
    passwd:     files winbind
    group:      files winbind
  6. Enable and start the winbind service:
    ~]# systemctl enable winbind
    ~]# systemctl start winbind
  7. Optionally, configure PAM using the authconf utility.
    For details, see the Using Pluggable Authentication Modules (PAM) section in the Red Hat System-Level Authentication Guide.
  8. Optionally for AD environments, configure the Kerberos client.
    For details, see the Configuring a Kerberos Client section in the Red Hat System-Level Authentication Guide.
15.1.10.1.2. Using the net rpc rights Command
In Windows, you can assign privileges to accounts and groups to perform special operations, such as setting ACLs on a share or upload printer drivers. On a Samba server, you can use the net rpc rights command to manage privileges.

Listing Privileges

To list all available privileges and their owners, use the net rpc rights list command. For example:
net rpc rights list -U "DOMAIN\administrator"
Enter DOMAIN\administrator's password:
     SeMachineAccountPrivilege  Add machines to domain
      SeTakeOwnershipPrivilege  Take ownership of files or other objects
             SeBackupPrivilege  Back up files and directories
            SeRestorePrivilege  Restore files and directories
     SeRemoteShutdownPrivilege  Force shutdown from a remote system
      SePrintOperatorPrivilege  Manage printers
           SeAddUsersPrivilege  Add users and groups to the domain
       SeDiskOperatorPrivilege  Manage disk shares
           SeSecurityPrivilege  System security

Granting Privileges

To grant a privilege to an account or group, use the net rpc rights grant command.
For example, grant the SePrintOperatorPrivilege privilege to the DOMAIN\printadmin group:
~]# net rpc rights grant "DOMAIN\printadmin" SePrintOperatorPrivilege \
       -U "DOMAIN\administrator"
Enter DOMAIN\administrator's password:
Successfully granted rights.

Revoking Privileges

To revoke a privilege from an account or group, use the net rpc rights revoke.
For example, to revoke the SePrintOperatorPrivilege privilege from the DOMAIN\printadmin group:
~]# net rpc rights remoke "DOMAIN\printadmin" SePrintOperatorPrivilege \
       -U "DOMAIN\administrator"
Enter DOMAIN\administrator's password:
Successfully revoked rights.
15.1.10.1.3. Using the net rpc share Command
The net rpc share command provides the capability to list, add, and remove shares on a local or remote Samba or Windows server.

Listing Shares

To list the shares on an SMB server, use the net rpc share list command. Optionally, pass the -S server_name parameter to the command to list the shares of a remote server. For example:
~]# net rpc share list -U "DOMAIN\administrator" -S example
Enter DOMAIN\administrator's password:
IPC$
share_1
share_2
...

Note

Shares hosted on a Samba server that have browseable = no set in their section in the /etc/samba/smb.conf file are not displayed in the output.

Adding a Share

The net rpc share add command enables you to add a share to an SMB server.
For example, to add a share named example on a remote Windows server that shares the C:\example\ directory:
~]# net rpc share add example="C:\example" -U "DOMAIN\administrator" -S server

Note

You must omit the trailing backslash in the path when specifying a Windows directory name.
To use the command to add a share to a Samba server:
  • The user specified in the -U parameter must have the SeDiskOperatorPrivilege privilege granted.
  • You must write a script that adds a share section to the /etc/samba/smb.conf file and reloads Samba. The script must be set in the add share command parameter in the [global] section in /etc/samba/smb.conf. For further details, see the add share command description in the smb.conf(5) man page.

Removing a Share

The net rpc share delete command enables you to remove a share from an SMB server.
For example, to remove the share named example from a remote Windows server:
~]# net rpc share delete example -U "DOMAIN\administrator" -S server
To use the command to remove a share from a Samba server:
  • The user specified in the -U parameter must have the SeDiskOperatorPrivilege privilege granted.
  • You must write a script that removes the share's section from the /etc/samba/smb.conf file and reloads Samba. The script must be set in the delete share command parameter in the [global] section in /etc/samba/smb.conf. For further details, see the delete share command description in the smb.conf(5) man page.
15.1.10.1.4. Using the net user Command
The net user command enables you to perform the following actions on an AD DC or NT4 PDC:
  • List all user accounts
  • Add users
  • Remove Users

Note

Specifying a connection method, such as ads for AD domains or rpc for NT4 domains, is only required when you list domain user accounts. Other user-related subcommands can auto-detect the connection method.
Pass the -U user_name parameter to the command to specify a user that is allowed to perform the requested action.

Listing Domain User Accounts

To list all users in an AD domain:
~]# net ads user -U "DOMAIN\administrator"
To list all users in an NT4 domain:
~]# net rpc user -U "DOMAIN\administrator"

Adding a User Account to the Domain

On a Samba domain member, you can use the net user add command to add a user account to the domain.
For example, add the user account to the domain:

Procedure 15.22. Adding a User Account to the Domain

  1. Add the account:
    ~]# net user add user password -U "DOMAIN\administrator"
    User user added
  2. Optionally, use the remote procedure call (RPC) shell to enable the account on the AD DC or NT4 PDC. For example:
    ~]# net rpc shell -U DOMAIN\administrator -S DC_or_PDC_name
    Talking to domain DOMAIN (S-1-5-21-1424831554-512457234-5642315751)
    
    net rpc> user edit disabled user no
    Set user's disabled flag from [yes] to [no]
    
    net rpc> exit
    

Deleting a User Account from the Domain

On a Samba domain member, you can use the net user delete command to remove a user account from the domain.
For example, to remove the user account from the domain:
~]# net user delete user -U "DOMAIN\administrator"
User user deleted
15.1.10.1.5. Using the net usershare Command

15.1.10.2. Using the rpcclient Utility

The rpcclient utility enables you to manually execute client-side Microsoft Remote Procedure Call (MS-RPC) functions on a local or remote SMB server. However, most of the features are integrated into separate utilities provided by Samba. Use rpcclient only for testing MS-PRC functions.
For example, you can use the utility to:
  • Manage the printer Spool Subsystem (SPOOLSS).

    Example 15.9. Assigning a Driver to a Printer

    ~]# rpcclient server_name -U "DOMAIN\administrator" \
           -c 'setdriver "printer_name" "driver_name"'
    Enter DOMAIN\administrators password:
    Successfully set printer_name to driver driver_name.
  • Retrieve information about an SMB server.

    Example 15.10. Listing all File Shares and Shared Printers

    ~]# rpcclient server_name -U "DOMAIN\administrator" -c 'netshareenum'
    Enter DOMAIN\administrators password:
    netname: Example_Share
    	remark:
    	path:   C:\srv\samba\example_share\
    	password:
    netname: Example_Printer
    	remark:
    	path:   C:\var\spool\samba\
    	password:
  • Perform actions using the Security Account Manager Remote (SAMR) protocol.

    Example 15.11. Listing Users on an SMB Server

    ~]# rpcclient server_name -U "DOMAIN\administrator" -c 'enumdomusers'
    Enter DOMAIN\administrators password:
    user:[user1] rid:[0x3e8]
    user:[user2] rid:[0x3e9]
    
    If you run the command against a standalone server or a domain member, it lists the users in the local database. Running the command against an AD DC or NT4 PDC lists the domain users.
For a complete list of supported subcommands, see COMMANDS section in the rpcclient(1) man page.

15.1.10.3. Using the samba-regedit Application

Certain settings, such as printer configurations, are stored in the registry on the Samba server. You can use the ncurses-based samba-regedit application to edit the registry of a Samba server.
To start the application, enter:
~]# samba-regedit
Use the following keys:
  • Cursor up and cursor down: Navigate through the registry tree and the values.
  • Enter: Opens a key or edits a value.
  • Tab: Switches between the Key and Value pane.
  • Ctrl+C: Closes the application.

15.1.10.5. Using the smbclient Utility

The smbclient utility enables you to access file shares on an SMB server, similarly to a command-line FTP client. You can use it, for example, to upload and download files to and from a share.
For example, to authenticate to the example share hosted on server using the DOMAIN\user account:
~]# smbclient -U "DOMAIN\user" //server/example
Enter domain\user's password:
Domain=[SERVER] OS=[Windows 6.1] Server=[Samba 4.6.2]
smb: \>
After smbclient connected successfully to the share, the utility enters the interactive mode and shows the following prompt:
smb: \>
To display all available commands in the interactive shell, enter:
smb: \> help
To display the help for a specific command, enter:
smb: \> help command_name
For further details and descriptions of the commands available in the interactive shell, see the smbclient(1) man page.
15.1.10.5.1. Using smbclient in Interactive Mode
If you use smbclient without the -c parameter, the utility enters the interactive mode.
The following procedure shows how to connect to an SMB share and download a file from a subdirectory:

Procedure 15.23. Downloading a File from an SMB Share Using smbclient

  1. Connect to the share:
    ~]# smbclient -U "DOMAIN\user_name" //server_name/share_name
  2. Change into the /example/ directory:
    smb: \> cd /example/
  3. List the files in the directory:
    smb: \example\> ls
      .                    D         0  Mon Sep 1 10:00:00 2017
      ..                   D         0  Mon Sep 1 10:00:00 2017
      example.txt          N   1048576  Mon Sep 1 10:00:00 2017
    
             9950208 blocks of size 1024. 8247144 blocks available
  4. Download the example.txt file:
    smb: \example\> get example.txt
    getting file \directory\subdirectory\example.txt of size 1048576 as example.txt (511975,0 KiloBytes/sec) (average 170666,7 KiloBytes/sec)
  5. Disconnect from the share:
    smb: \example\> exit
15.1.10.5.2. Using smbclient in Scripting Mode
If you pass the -c commands parameter to smbclient, you can automatically execute the commands on the remote SMB share. This enables you to use smbclient in scripts.
The following command shows how to connect to an SMB share and download a file from a subdirectory:
~]# smbclient -U DOMAIN\user_name //server_name/share_name \
       -c "cd /example/ ; get example.txt ; exit"

15.1.10.6. Using the smbcontrol Utility

The smbcontrol utility enables you to send command messages to the smbd, nmbd, winbindd, or all of these services. These control messages instruct the service, for example, to reload its configuration.

Example 15.12. Reloading the Configuration of the smbd, nmbd, and winbindd Service

For example, to reload the configuration of the smbd, nmbd, winbindd, send the reload-config message-type to the all destination:
~]# smbcontrol all reload-config
For further details and a list of available command message types, see the smbcontrol(1) man page.

15.1.10.7. Using the smbpasswd Utility

The smbpasswd utility manages user accounts and passwords in the local Samba database.
If you run the command as a user, smbpasswd changes the Samba password of the user. For example:
[user@server ~]$ smbpasswd
New SMB password:
Retype new SMB password:
If you run smbpasswd as the root user, you can use the utility, for example, to:
  • Create a new user:
    [root@server ~]# smbpasswd -a user_name
    New SMB password:
    Retype new SMB password:
    Added user user_name.

    Note

    Before you can add a user to the Samba database, you must create the account in the local operating system. See Section 3.3.1, “Adding a New User”
  • Enable a Samba user:
    [root@server ~]# smbpasswd -e user_name
    Enabled user user_name.
  • Disable a Samba user:
    [root@server ~]# smbpasswd -x user_name
    Disabled user user_name.
  • Delete a user:
    [root@server ~]# smbpasswd -x user_name
    Deleted user user_name.
For further details, see the smbpasswd(8) man page.

15.1.10.8. Using the smbstatus Utility

The smbstatus utility reports on:
  • Connections per PID of each smbd daemon to the Samba server. This report includes the user name, primary group, SMB protocol version, encryption, and signing information.
  • Connections per Samba share. This report includes the PID of the smbd daemon, the IP of the connecting machine, the time stamp when the connection was established, encryption, and signing information.
  • A list of locked files. The report entries include further details, such as opportunistic lock (oplock) types

Example 15.13. Output of the smbstatus Utility

~]# smbstatus

Samba version 4.6.2
PID  Username              Group                Machine                            Protocol Version  Encryption  Signing
-----------------------------------------------------------------------------------------------------------------------------
963  DOMAIN\administrator  DOMAIN\domain users  client-pc  (ipv4:192.0.2.1:57786)  SMB3_02           -           AES-128-CMAC

Service  pid  Machine    Connected at                  Encryption  Signing:
-------------------------------------------------------------------------------
example  969  192.0.2.1  Mo Sep  1 10:00:00 2017 CEST  -           AES-128-CMAC

Locked files:
Pid  Uid    DenyMode   Access    R/W     Oplock      SharePath           Name      Time
------------------------------------------------------------------------------------------------------------
969  10000  DENY_WRITE 0x120089  RDONLY  LEASE(RWH)  /srv/samba/example  file.txt  Mon Sep  1 10:00:00 2017
For further details, see the smbstatus(1) man page.

15.1.10.9. Using the smbtar Utility

The smbtar utility backs up the content of an SMB share or a subdirectory of it and stores the content in a tar archive. Alternatively, you can write the content to a tape device.
For example, to back up the content of the demo directory on the //server/example/ share and store the content in the /root/example.tar archive:
~]# smbtar -s server -x example -u user_name -p password -t /root/example.tar
For further details, see the smbtar(1) man page.

15.1.10.11. Using the wbinfo Utility

The wbinfo utility queries and returns information created and used by the winbindd service.

Note

The winbindd service must be configured and running to use wbinfo.
You can use wbinfo, for example, to:
  • List domain users:
    ~]# wbinfo -u
    AD\administrator
    AD\guest
    ...
  • List domain groups:
    ~]# wbinfo -g
    AD\domain computers
    AD\domain admins
    AD\domain users
    ...
  • Display the SID of a user:
    ~]# wbinfo --name-to-sid="AD\administrator"
    S-1-5-21-1762709870-351891212-3141221786-500 SID_USER (1)
  • Display information about domains and trusts:
    ~]# wbinfo --trusted-domains --verbose
    Domain Name   DNS Domain            Trust Type  Transitive  In   Out
    BUILTIN                             None        Yes         Yes  Yes
    server                              None        Yes         Yes  Yes
    DOMAIN1       domain1.example.com   None        Yes         Yes  Yes
    DOMAIN2       domain2.example.com   External    No          Yes  Yes
For further details, see the wbinfo(1) man page.

15.1.11. Additional Resources

  • The Red Hat Samba packages include manual pages for all Samba commands and configuration files the package installs. For example, to display the man page of the /etc/samba/smb.conf file that explains all configuration parameters you can set in this file:
    ~]# man 5 smb.conf
  • /usr/share/docs/samba-version/: Contains general documentation, example scripts, and LDAP schema files, provided by the Samba project.
  • Red Hat Cluster Storage Administration Guide: Provides information about setting up Samba and the Clustered Trivial Database (CDTB) to share directories stored on an GlusterFS volume.
  • The Clustered Samba Configuration section in the Red Hat Enterprise Linux 6 Cluster Administration Guide describes how to set up a Samba high-availability installation.
    This documentation is currently not available for the latest Red Hat Enterprise Linux version.