Difference between revisions of "Updating Samba"

(Added "Samba AD DC Database Check" section + setting links to the new section to prevent duplicate content.)
(Upgrading Active Directory Domain Controllers)
 
(32 intermediate revisions by 6 users not shown)
Line 3: Line 3:
 
The following documentation describes the process of updating Samba to a newer version.
 
The following documentation describes the process of updating Samba to a newer version.
  
If you want to migrate a Samba NT4 domain to Samba Active Directory (AD), see [[Migrating_a_Samba_NT4_domain_to_a_Samba_AD_domain_(classic_upgrade)|Migrating a Samba NT4 Domain to Samba Active Directory (Classic Upgrade)]].
+
If you want to migrate a Samba NT4 domain to Samba Active Directory (AD), see [[Migrating_a_Samba_NT4_Domain_to_Samba_AD_(Classic_Upgrade)|Migrating a Samba NT4 Domain to Samba AD (Classic Upgrade)]].
  
 +
{{Imbox
 +
| type = note
 +
| text = Microsoft stopped supporting Windows NT 4.0 on December 31, 2004 and twice recently they have broken compatibility to it in Windows 10. It is probably just a matter of time until they decide not to fix a break. Samba, like Microsoft, advises upgrading to Active Directory.
 +
}}
  
  
== Common Misconceptions About Samba 4 ==
 
  
One of the common misconceptions is: <u>"Samba 4" means "Active Directory only": '''This is wrong.'''</u>
 
  
The Active Directory (AD) Domain Controller (DC) support is one of the enhancements in Samba 4.0. However all newer versions include the features of previous versions - including the NT4-style (classic) domain support. This means you can [[#The_Update_Process|update]] a Samba 3.x NT4-style PDC to a recent version, like you updated in the past - for example from 3.4.x to 3.5.x. There is no need to migrate an NT4-style domain to an AD.
 
  
Additionally, all recent versions continue to support setting up a new NT4-style PDC. The AD support in Samba 4.0 and later is optional and does not replace any for the PDC feature. The Samba team understand the difficulty presented by existing LDAP structures. For that reason, there is no plan to remove the classic PDC support. Additionally we continue testing the PDC support in our continuous integration system.
+
= Misconceptions About Samba 4 =
  
 +
{{Imbox
 +
| type = note
 +
| text = If you update to Samba 4 and later, you do not have to migrate to Active Directory.
 +
}}
  
 +
The Active Directory (AD) Domain Controller (DC) support is one of the enhancements introduced in Samba 4.0. However all newer versions include the features of previous versions - including the NT4-style (classic) domain support. This means you can [[#The_Update_Process|update]] a Samba 3.x NT4-style primary domain controller (PDC) to a recent version, as you previously updated, for example from 3.4.x to 3.5.x. There is no need to migrate an NT4-style domain to an AD.
  
 
+
Additionally, all recent versions continue to support setting up a new NT4-style PDC. The AD support in Samba 4.0 and later is optional and does not replace any of the PDC features. The Samba team understand the difficulty presented by existing LDAP structures. For that reason, there is no plan to remove the classic PDC support. Additionally we continue testing the PDC support in our continuous integration system.
 
 
= Updating Multiple Samba Domain Controllers =
 
 
 
If you are updating multiple Samba Active Directory (AD) Domain Controllers (DC), the recommended order is:
 
 
 
* Update one Samba AD DC that is is not holding any flexible single master operations (FSMO) role.
 
 
 
* Start Samba on the updated DC.
 
 
 
* Verify that the directory replication between all DCs is working correctly:
 
# samba-tool drs showrepl
 
 
 
* Test the installation to ensure that the new version works correctly.
 
 
 
* Upgrade all other Samba DCs one at a time and always verify that the replication is working correctly.
 
  
  
Line 40: Line 31:
 
= The Update Process =
 
= The Update Process =
  
Run the following steps, regardless if you are updating a Samba Active Directory (AD) domain controller (DC), a Samba NT4-style PDC, a Samba domain member, or a standalone installation:
+
Run the following steps, whether you are updating a Samba Active Directory (AD) domain controller (DC), a Samba NT4-style PDC, a Samba domain member, or a standalone installation:
  
 
* Stop all Samba services.
 
* Stop all Samba services.
Line 46: Line 37:
 
* Create a backup.
 
* Create a backup.
  
* Read all release notes of versions since the one you are updating from. They contain important information on new features, changed parameter options, and so on.
+
* Read the release notes of skipped versions. They contain important information, such as new features, changed parameter, and bug fixes. In case you switch to new major release, read the release notes of the initial version (x.y.0) and the ones from minor versions up to the new version you will update to. For example, if you update from 4.4.4 to 4.6.2, read the 4.5.0, 4.6.0, 4.6.1, and 4.6.2 release notes.
  
 
* Install the latest version over your existing one:
 
* Install the latest version over your existing one:
  
:* If you compile Samba from the sources, use the same "configure" options like for your previous version. For more information, see [[Build_Samba_from_source#Viewing_Built_Options_of_an_Existing_Installation|Build Samba From the Sources]].
+
:* If you compile Samba from the sources, use the same <code>configure</code> options as used for your previous version. For more information, see [[Build_Samba_from_Source#Viewing_Built_Options_of_an_Existing_Installation|Build Samba From the Sources]].
  
 
:* If you update using packages, read the distribution documentation for information how to update.
 
:* If you update using packages, read the distribution documentation for information how to update.
  
 
* Start Samba.
 
* Start Samba.
: Start the same daemons like for your previous version:
+
: Start the same daemons as on your previous version:
:* On Samba AD DCs: samba
+
:* On Samba AD DCs: <code>samba</code>
:* On Samba NT4-style PDC/BDCs: smbd, nmbd
+
:* On Samba NT4-style PDC/BDCs: <code>smbd</code>, <code>nmbd</code>
:* On Samba domain members: smbd, nmbd (winbind, if used)
+
:* On Samba domain members: <code>smbd</code>, <code>nmbd</code> (<code>winbind</code>, if used)
:* On Samba standalone hosts: smbd
+
:* On Samba standalone hosts: <code>smbd</code>
 
 
* Only on Samba AD DCs: Run the [[#Samba_AD_DC_Database_Check|Samba AD DC database check]].
 
  
 
* Check your Samba log files for errors.
 
* Check your Samba log files for errors.
Line 68: Line 57:
  
  
 +
= Upgrading Active Directory Domain Controllers =
  
 +
Upgrading your AD DCs can introduce additional complications, due to things like database compatibility and managing FSMO roles. We recommend that you:
 +
* Run the [[dbcheck|Samba AD DC database check]] as part of testing your updated installation.
 +
* Refer to [[Upgrading_a_Samba_AD_DC#Updating_Multiple_Samba_Domain_Controllers|Updating_Multiple_Samba_Domain_Controllers]] for the safest way to roll out an upgrade to your DC network.
 +
* Be aware of database compatibility when [[downgrading an Active Directory DC]] across a major release.
 +
<br>
  
 +
= Notable Enhancements and Changes =
  
= Samba AD DC Database Check =
+
If you are updating Samba, always read the [[Samba_Features_added/changed_(by_release)|release notes]] of all versions between the previous and the one you are updating to. They contain important and additional information on new features, changed parameter options, and so on.
  
The "samba-tool" utility enables you to detect and fix problems in the Samba Active Directory (AD) database. For example, if a previous Samba version stored an attribute incorrectly and the updated version fixes the problem. You must run the check and fix command on every Samba AD DC locally, because some fixes apply to non-replicated attributes and modifications are not replicated to other DCs.
+
This section provides an overview about important changes that require your attention to fix problems of previous versions, avoid a negative performance impact, and so on.
  
To check the AD database, run:
 
  
# samba-tool dbcheck --cross-ncs
 
  
To fix reported errors, run:
+
== Changes Affecting All Samba Installation Modes ==
  
# samba-tool dbcheck --cross-ncs --fix
+
=== File Execution Permissions ===
  
If you pass the "--yes" parameter to the command, all questions are automatically answered with "yes". Note that if you omit the "--yes" parameter, the database check executes three fsync() calls for each object. This can result result in a longer run duration. For example, passing the "--yes" parameter to the command fixed 3500 objects in 10 seconds in our test environment. Without this parameter, the command required 4:50 minutes for the same operation.
+
'''4.0.0 and later'''
  
After a repair, re-check the database to verify a successful operation.
+
Previously, Samba did not check the execution bit of files. As a consequence, users could execute files, such as <code>*.exe</code> and <code>*.bat</code>, on a share, if the x-bit was not set. Samba has been enhanced and now denies to execute a file if the x-bit is not set. In situations, such as when upgrading from a previous version, your executable files can be missing the x-bit. As a workaround, you can enable the old behaviour, if you set the following parameter for individual shares or in the <code>[global]</code> section:
  
 +
acl allow execute always = yes
  
  
  
 +
== Samba Active Directory Domain Controllers ==
  
= Notable Enhancements and Changes =
+
=== The <code>ntvfs</code> File Server Back End Has Been Disabled ===
 
 
This section provides a list of notable enhancements and changes. In any case, read all release notes of versions between the previous and the new one. They contain important and additional information on new features, changed parameter options, and so on.
 
  
 +
'''4.5.0 and later'''
  
 +
Previously, Samba enabled users to provision a domain controller (DC) using the <code>ntvfs</code> file server back end. This back end was never supported, and thus the <code>ntvfs</code> feature is no longer build by default in Samba 4.5.0. Consequently, starting the <code>samba</code> service on a DC using the <code>ntvfs</code> back end failed after the update and the following error is logged:
  
== All Samba Installations ==
+
[2016/09/01 08:00:00.000000,  0, pid=995] ../source4/smbd/service.c:98(server_service_startup)
 +
  Failed to start service 'smb' - NT_STATUS_INVALID_SYSTEM_SERVICE
 +
[2016/09/01 08:00:00.000000,  0, pid=995] ../lib/util/become_daemon.c:111(exit_daemon)
 +
  STATUS=daemon failed to start: Samba failed to start services, error code -1073741796
  
=== File Execution Permissions ===
+
To fix the problem, migrate the file server back end on your DC to the supported <code>s3fs</code> back end. For details, see [[Migrating_the_ntvfs_File_Server_Back_End_to_s3fs|Migrating the ntvfs File Server Back End to s3fs]].
  
'''Updating to 4.0.0 and later'''
 
  
For more information, see [[Shares_with_POSIX_ACLs#Execute_bit_on_files|Execution of files]].
 
 
 
 
== Samba Active Directory Domain Controllers ==
 
  
 
=== Fixing replPropertyMetaData Attributes ===
 
=== Fixing replPropertyMetaData Attributes ===
  
'''Updating to 4.5.0 and later'''
+
'''4.5.0 and later'''
  
Samba versions prior 4.5.0 stored the "replPropertyMetaData" attribute incorrectly. As a consequence, administrators could experience, for example, renaming conflicts. The problem has been fixed in 4.5.0 and later versions and Samba now stores the attribute correctly. The "samba-tool" utility has been enhanced to detect incorrectly stored "replPropertyMetaData" attributes:
+
Samba versions prior to 4.5.0 stored the <code>replPropertyMetaData</code> attribute incorrectly. As a consequence, administrators could experience, for example, renaming conflicts. The problem has been fixed in 4.5.0 and later versions and Samba now stores the attribute correctly. The <code>samba-tool</code> utility has been enhanced to detect incorrectly stored <code>replPropertyMetaData</code> attributes:
  
 
  # samba-tool dbcheck --cross-ncs
 
  # samba-tool dbcheck --cross-ncs
Line 128: Line 121:
 
  Fixed attribute 'replPropertyMetaData' of 'CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com'
 
  Fixed attribute 'replPropertyMetaData' of 'CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com'
  
Note that the "--yes" parameter automatically fixes <u>all</u> problems found and not only the "replPropertyMetaData" attributes!
+
Note that the <code>--yes</code> parameter automatically fixes <u>all</u> problems found and not only the <code>replPropertyMetaData</code> attributes!
  
Run the check and fix operation on all Domain Controllers (DC), because "replPropertyMetaData" is a non-replicated attribute and modifications are not replicated to other DCs.
+
Run the check and fix operation on all Samba Domain Controllers (DC), because <code>replPropertyMetaData</code> is a non-replicated attribute and modifications are not replicated to other DCs.
  
For more information, see the [[#Samba_AD_DC_Database_Check|Samba AD DC database check]] section.
+
For more information, see the [[Dbcheck|Samba AD DC database check]] section.
  
 +
=== Failure To Access Shares on Domain Controllers If <code>idmap config</code> Parameters Set in the <code>smb.conf</code> File ===
  
 +
'''4.4.6 or later'''
  
 +
The <code>winbindd</code> service on a Samba Active Directory (AD) domain controller (DC) automatically uses the IDs set in the Active Directory <code>uidNumber</code> and <code>gidNumber</code> attributes of user accounts and groups. If the attributes are not set, Samba generates IDs locally on the DC and stores them in the <code>idmap.ldb</code> database. Thus, on a Samba AD DC, <code>idmap config</code> parameters set in the <code>smb.conf</code> file were ignored. Due to a bug in Samba 4.4.6 and later, the parameters are no longer ignored and clients fail to connect to shares on the DC. To fix the problem:
 +
* Remove all <code>idmap config</code> parameters in the <code>smb.conf</code> file on DCs.
 +
* Restart the <code>samba</code> service.
 +
* Restart the clients.
  
 +
As a result, clients now correctly connect to shares on the DC.
  
=== Default for LDAP Connections Requires Strong Authentication ===
 
  
'''Updating to 4.4.1 or later / 4.3.7 or later / 4.2.10 or later'''
 
  
The security updates 4.4.1, 4.3.7 and 4.2.10 introduced a new smb.conf option for the Active Directory (AD) LDAP server to enforce strong authentication. The default for this new option "ldap server require strong auth" is "yes" and allows only simple binds over TLS encrypted connections. In consequence, external applications that connect to AD using LDAP, cannot establish a connection if they do not use or support TLS encrypted connections.
+
=== New Default for LDAP Connections Requires Strong Authentication ===
  
Applications connecting to Samba AD using the LDAP protocol without encryption, are displaying error messages like:
+
'''4.4.1 or later / 4.3.7 or later / 4.2.10 or later'''
 +
 
 +
The security updates 4.4.1, 4.3.7 and 4.2.10 introduced a new <code>smb.conf</code> option for the Active Directory (AD) LDAP server to enforce strong authentication. The default for this new option <code>ldap server require strong auth</code> is <code>yes</code> and allows only simple binds over TLS encrypted connections. In consequence, external applications that connect to AD using LDAP, cannot establish a connection if they do not use or support TLS encrypted connections.
 +
 
 +
Applications connecting to Samba AD using the LDAP protocol without encryption, will display the error message:
  
 
  ldap_bind: Strong(er) authentication required (8)
 
  ldap_bind: Strong(er) authentication required (8)
Line 155: Line 157:
 
=== AD Database Cleanup of Deleted LDAP DNS Entries ===
 
=== AD Database Cleanup of Deleted LDAP DNS Entries ===
  
'''Updating to 4.1.12 or later'''
+
'''4.1.12 or later'''
  
Previously, Samba incorrectly created many deleted Active Directory (AD) objects for removed DNS entries. The problem has been fixed. If you start the first Domain Controller (DC) with a fixed Samba version, all deleted objects are removed. As a result, this can result in a slow performance until the deleted objects are removed.
+
Previously, Samba incorrectly created deleted Active Directory (AD) objects for removed DNS entries. The problem has been fixed. If you start the first Domain Controller (DC) with a fixed Samba version, all deleted objects are removed. As a result, this can result in a slow performance until the deleted objects are removed.
  
  
Line 163: Line 165:
 
=== Incorrect TLS File Permissions ===
 
=== Incorrect TLS File Permissions ===
  
'''Updating to 4.1.2 or later / 4.0.12 or later'''
+
'''4.1.2 or later / 4.0.12 or later'''
  
Previously, Samba created the *.pem files used for LDAP TLS encryptions with insecure permissions. To avoid insecure connections, delete the files on all domain controllers (DC):
+
Previously, Samba created the <code>*.pem</code> files used for LDAP TLS encryptions with insecure permissions. To avoid insecure connections, delete the files on all domain controllers (DC):
  
 
  # rm /usr/local/samba/private/tls/*.pem
 
  # rm /usr/local/samba/private/tls/*.pem
Line 173: Line 175:
  
  
=== Fixing dynamic DNS update problems ===
+
=== Fixing Dynamic DNS Update Problems ===
  
'''Updating to 4.0.7 or later'''
+
'''4.0.7 or later'''
  
 
See [[Fix_DNS_dynamic_updates_in_Samba_versions_prior_4.0.7|Fix DNS dynamic updates in Samba versions prior 4.0.7]] for details.
 
See [[Fix_DNS_dynamic_updates_in_Samba_versions_prior_4.0.7|Fix DNS dynamic updates in Samba versions prior 4.0.7]] for details.
Line 181: Line 183:
  
  
=== Fixing incorrect Sysvol and Directory ACLs ===
+
=== Fixing Incorrect Sysvol and Directory ACLs ===
  
''' Updating from early 4.0.x versions, 4.0 beta and 4.0 release candidates'''
+
''' When updating from early 4.0.x versions, 4.0 beta and 4.0 release candidates.'''
  
 
* To reset wrong Sysvol ACLs, run:
 
* To reset wrong Sysvol ACLs, run:
Line 194: Line 196:
 
  # samba-tool dbcheck --cross-ncs --fix
 
  # samba-tool dbcheck --cross-ncs --fix
  
 +
== Samba Domain Members ==
 +
 +
=== ID Mapping Configuration Verification ===
 +
 +
'''4.6.0 or later'''
  
 +
Previously, Samba did not verified the ID mapping configuration in the <code>smb.conf</code> file on a domain member. Thus, users could set an incorrect ID mapping configuration, such as overlapping ID ranges or incorrect back ends for the default domain. Consequently, the <code>winbindd</code> service started and ID mapping failed or did not work as expected. The <code>testparm</code> utility has been enhanced and now reports incorrect ID mapping configurations. For example:
  
== Samba Domain Members ==
+
ERROR: The idmap range for the domain * (tdb) overlaps with the range of SAMDOM (ad)!
 +
 
 +
ERROR: Do not use the 'ad' backend as the default idmap backend!
 +
 
 +
Additionally, when using an incorrect ID mapping configuration, the <code>winbindd</code> service now fails to start and an error message is logged. For example:
 +
 
 +
[2017/03/01 12:00:00.000000,  0, pid=980] ../source3/winbindd/winbindd.c:1705(main)
 +
  main: FATAL: Invalid idmap backend ad configured as the default backend!
 +
 
 +
Using Samba 4.6.0 and later, users are no longer able to use incorrect ID mapping configurations.
 +
 
 +
For further details, supported back ends on a domain member, and their configuration, see:
 +
* [[Identity Mapping Back Ends]]
 +
* the <code>IDENTITY MAPPING CONSIDERATIONS</code> section in the <code>smb.conf(5)</code> man page
 +
 
 +
 
 +
 
 +
=== The <code>ad</code> ID Mapping Back End Now Supports Enabling RFC2307 or Template Mode Per-domain ===
 +
 
 +
'''4.6.0 or later'''
 +
 
 +
Previously, when the <code>winbind nss info</code> parameter was set to <code>rfc2307</code>, the Samba <code>ad</code> ID mapping back end retrieved shell and home directory settings for all Active Directory (AD) domains from AD. In Samba 4.6.0, the new <code>idmap config ''domain_name'':unix_nss_info</code> parameter has been added. This parameter enables the administrator to set on a per-AD domain basis if the shell and home directory settings of users should be retrieved from AD or if the template settings, set in the <code>template shell</code> and <code>template homedir</code> parameters are applied.
 +
 
 +
The new <code>idmap config ''domain_name'':unix_nss_info</code> parameter has a higher priority than the global <code>winbind nss info = rfc2307</code> setting. Therefore, using the <code>idmap config ''domain_name'':unix_nss_info = no</code> default setting for an AD domain, the shell and home directory are no longer retrieved from AD and the values set in the <code>template shell</code> and <code>template homedir</code> parameters are applied. To re-enable retrieving the values from AD for a domain, set in the <code>[global]</code>section in your <code>smb.conf</code> file:
 +
 
 +
idmap config ''domain_name'':unix_nss_info = yes
  
No remarkable important changes.
+
For details and an example how to set up, see [[Idmap_config_ad#Configuring_the_ad_Back_End|idmap config ad - Configuring the ad Back End]].

Latest revision as of 03:38, 1 August 2019

Introduction

The following documentation describes the process of updating Samba to a newer version.

If you want to migrate a Samba NT4 domain to Samba Active Directory (AD), see Migrating a Samba NT4 Domain to Samba AD (Classic Upgrade).



Misconceptions About Samba 4

The Active Directory (AD) Domain Controller (DC) support is one of the enhancements introduced in Samba 4.0. However all newer versions include the features of previous versions - including the NT4-style (classic) domain support. This means you can update a Samba 3.x NT4-style primary domain controller (PDC) to a recent version, as you previously updated, for example from 3.4.x to 3.5.x. There is no need to migrate an NT4-style domain to an AD.

Additionally, all recent versions continue to support setting up a new NT4-style PDC. The AD support in Samba 4.0 and later is optional and does not replace any of the PDC features. The Samba team understand the difficulty presented by existing LDAP structures. For that reason, there is no plan to remove the classic PDC support. Additionally we continue testing the PDC support in our continuous integration system.



The Update Process

Run the following steps, whether you are updating a Samba Active Directory (AD) domain controller (DC), a Samba NT4-style PDC, a Samba domain member, or a standalone installation:

  • Stop all Samba services.
  • Create a backup.
  • Read the release notes of skipped versions. They contain important information, such as new features, changed parameter, and bug fixes. In case you switch to new major release, read the release notes of the initial version (x.y.0) and the ones from minor versions up to the new version you will update to. For example, if you update from 4.4.4 to 4.6.2, read the 4.5.0, 4.6.0, 4.6.1, and 4.6.2 release notes.
  • Install the latest version over your existing one:
  • If you compile Samba from the sources, use the same configure options as used for your previous version. For more information, see Build Samba From the Sources.
  • If you update using packages, read the distribution documentation for information how to update.
  • Start Samba.
Start the same daemons as on your previous version:
  • On Samba AD DCs: samba
  • On Samba NT4-style PDC/BDCs: smbd, nmbd
  • On Samba domain members: smbd, nmbd (winbind, if used)
  • On Samba standalone hosts: smbd
  • Check your Samba log files for errors.
  • Test your updated installation.


Upgrading Active Directory Domain Controllers

Upgrading your AD DCs can introduce additional complications, due to things like database compatibility and managing FSMO roles. We recommend that you:


Notable Enhancements and Changes

If you are updating Samba, always read the release notes of all versions between the previous and the one you are updating to. They contain important and additional information on new features, changed parameter options, and so on.

This section provides an overview about important changes that require your attention to fix problems of previous versions, avoid a negative performance impact, and so on.


Changes Affecting All Samba Installation Modes

File Execution Permissions

4.0.0 and later

Previously, Samba did not check the execution bit of files. As a consequence, users could execute files, such as *.exe and *.bat, on a share, if the x-bit was not set. Samba has been enhanced and now denies to execute a file if the x-bit is not set. In situations, such as when upgrading from a previous version, your executable files can be missing the x-bit. As a workaround, you can enable the old behaviour, if you set the following parameter for individual shares or in the [global] section:

acl allow execute always = yes


Samba Active Directory Domain Controllers

The ntvfs File Server Back End Has Been Disabled

4.5.0 and later

Previously, Samba enabled users to provision a domain controller (DC) using the ntvfs file server back end. This back end was never supported, and thus the ntvfs feature is no longer build by default in Samba 4.5.0. Consequently, starting the samba service on a DC using the ntvfs back end failed after the update and the following error is logged:

[2016/09/01 08:00:00.000000,  0, pid=995] ../source4/smbd/service.c:98(server_service_startup)
  Failed to start service 'smb' - NT_STATUS_INVALID_SYSTEM_SERVICE
[2016/09/01 08:00:00.000000,  0, pid=995] ../lib/util/become_daemon.c:111(exit_daemon)
  STATUS=daemon failed to start: Samba failed to start services, error code -1073741796

To fix the problem, migrate the file server back end on your DC to the supported s3fs back end. For details, see Migrating the ntvfs File Server Back End to s3fs.


Fixing replPropertyMetaData Attributes

4.5.0 and later

Samba versions prior to 4.5.0 stored the replPropertyMetaData attribute incorrectly. As a consequence, administrators could experience, for example, renaming conflicts. The problem has been fixed in 4.5.0 and later versions and Samba now stores the attribute correctly. The samba-tool utility has been enhanced to detect incorrectly stored replPropertyMetaData attributes:

# samba-tool dbcheck --cross-ncs

To fix the attributes, run:

# samba-tool dbcheck --cross-ncs --fix --yes
...
CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com: 0x00000003
CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com: 0x00000000
ERROR: unsorted attributeID values in replPropertyMetaData on CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com

Fix replPropertyMetaData on CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com by sorting the attribute list? [YES]
Fixed attribute 'replPropertyMetaData' of 'CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com'

Note that the --yes parameter automatically fixes all problems found and not only the replPropertyMetaData attributes!

Run the check and fix operation on all Samba Domain Controllers (DC), because replPropertyMetaData is a non-replicated attribute and modifications are not replicated to other DCs.

For more information, see the Samba AD DC database check section.

Failure To Access Shares on Domain Controllers If idmap config Parameters Set in the smb.conf File

4.4.6 or later

The winbindd service on a Samba Active Directory (AD) domain controller (DC) automatically uses the IDs set in the Active Directory uidNumber and gidNumber attributes of user accounts and groups. If the attributes are not set, Samba generates IDs locally on the DC and stores them in the idmap.ldb database. Thus, on a Samba AD DC, idmap config parameters set in the smb.conf file were ignored. Due to a bug in Samba 4.4.6 and later, the parameters are no longer ignored and clients fail to connect to shares on the DC. To fix the problem:

  • Remove all idmap config parameters in the smb.conf file on DCs.
  • Restart the samba service.
  • Restart the clients.

As a result, clients now correctly connect to shares on the DC.


New Default for LDAP Connections Requires Strong Authentication

4.4.1 or later / 4.3.7 or later / 4.2.10 or later

The security updates 4.4.1, 4.3.7 and 4.2.10 introduced a new smb.conf option for the Active Directory (AD) LDAP server to enforce strong authentication. The default for this new option ldap server require strong auth is yes and allows only simple binds over TLS encrypted connections. In consequence, external applications that connect to AD using LDAP, cannot establish a connection if they do not use or support TLS encrypted connections.

Applications connecting to Samba AD using the LDAP protocol without encryption, will display the error message:

ldap_bind: Strong(er) authentication required (8)
       additional info: BindSimple: Transport encryption required.

For further information, see the 4.4.1, 4.3.7, or the 4.2.10 release notes.


AD Database Cleanup of Deleted LDAP DNS Entries

4.1.12 or later

Previously, Samba incorrectly created deleted Active Directory (AD) objects for removed DNS entries. The problem has been fixed. If you start the first Domain Controller (DC) with a fixed Samba version, all deleted objects are removed. As a result, this can result in a slow performance until the deleted objects are removed.


Incorrect TLS File Permissions

4.1.2 or later / 4.0.12 or later

Previously, Samba created the *.pem files used for LDAP TLS encryptions with insecure permissions. To avoid insecure connections, delete the files on all domain controllers (DC):

# rm /usr/local/samba/private/tls/*.pem

Restart Samba after you deleted the files to automatically re-create the new certificates.


Fixing Dynamic DNS Update Problems

4.0.7 or later

See Fix DNS dynamic updates in Samba versions prior 4.0.7 for details.


Fixing Incorrect Sysvol and Directory ACLs

When updating from early 4.0.x versions, 4.0 beta and 4.0 release candidates.

  • To reset wrong Sysvol ACLs, run:
# samba-tool ntacl sysvolreset
  • To reset all well known ACLs in the directory, run:
# samba-tool dbcheck --cross-ncs --reset-well-known-acls --fix
  • To fix errors in the Active Directory (AD) database, run:
# samba-tool dbcheck --cross-ncs --fix

Samba Domain Members

ID Mapping Configuration Verification

4.6.0 or later

Previously, Samba did not verified the ID mapping configuration in the smb.conf file on a domain member. Thus, users could set an incorrect ID mapping configuration, such as overlapping ID ranges or incorrect back ends for the default domain. Consequently, the winbindd service started and ID mapping failed or did not work as expected. The testparm utility has been enhanced and now reports incorrect ID mapping configurations. For example:

ERROR: The idmap range for the domain * (tdb) overlaps with the range of SAMDOM (ad)!
ERROR: Do not use the 'ad' backend as the default idmap backend!

Additionally, when using an incorrect ID mapping configuration, the winbindd service now fails to start and an error message is logged. For example:

[2017/03/01 12:00:00.000000,  0, pid=980] ../source3/winbindd/winbindd.c:1705(main)
  main: FATAL: Invalid idmap backend ad configured as the default backend!

Using Samba 4.6.0 and later, users are no longer able to use incorrect ID mapping configurations.

For further details, supported back ends on a domain member, and their configuration, see:


The ad ID Mapping Back End Now Supports Enabling RFC2307 or Template Mode Per-domain

4.6.0 or later

Previously, when the winbind nss info parameter was set to rfc2307, the Samba ad ID mapping back end retrieved shell and home directory settings for all Active Directory (AD) domains from AD. In Samba 4.6.0, the new idmap config domain_name:unix_nss_info parameter has been added. This parameter enables the administrator to set on a per-AD domain basis if the shell and home directory settings of users should be retrieved from AD or if the template settings, set in the template shell and template homedir parameters are applied.

The new idmap config domain_name:unix_nss_info parameter has a higher priority than the global winbind nss info = rfc2307 setting. Therefore, using the idmap config domain_name:unix_nss_info = no default setting for an AD domain, the shell and home directory are no longer retrieved from AD and the values set in the template shell and template homedir parameters are applied. To re-enable retrieving the values from AD for a domain, set in the [global]section in your smb.conf file:

idmap config domain_name:unix_nss_info = yes

For details and an example how to set up, see idmap config ad - Configuring the ad Back End.