Samba 4.5 Features added/changed

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Samba 4.5.0rc1

Release Notes for Samba 4.5.0rc1
July 28, 2016

Release Announcements

This is the first preview release of Samba 4.5. This is *not* intended for production environments and is designed for testing purposes only. Please report any defects via the Samba bug reporting system at

Samba 4.5 will be the next version of the Samba suite.


NTLMv1 authentication disabled by default

In order to improve security we have changed the default value for the "ntlm auth" option from "yes" to "no". This may have impact on very old client which doesn't support NTLMv2 yet.

The primary user of NTLMv1 is MSCHAPv2 for VPNs and 802.1x.

By default Samba will only allow NTLMv2 via NTLMSSP now, as we have the following default "lanman auth = no", "ntlm auth = no" and "raw NTLMv2 auth = no".



The ldap server has support for the LDAP_SERVER_NOTIFICATION_OID control. This can be used to monitor the active directory database for changes.

KCC improvements for sparse network replication

The Samba KCC will now be the default knowledge consistency checker in Samba AD. Instead of using full mesh replication between every DC, the KCC will set up connections to optimize replication latency and cost (using site links to calculate the routes). This change should allow larger domains to function significantly better in terms of replication traffic and the time spent performing DRS replication.

VLV - Virtual List View

The VLV Control allows applications to page the LDAP directory in the way you might expect a live phone book application to operate, without first downloading the entire directory.

DRS Replication for the AD DC

DRS Replication in Samba 4.5 is now much more efficient in handling linked attributes, particularly in large domains with over 1000 group memberships or other links.

Replication is also much more reliable in the handling of tree renames, such as the rename of an organizational unit containing many users. Extensive tests have been added to ensure this code remains reliable, particularly in the case of conflicts between objects added with the same name on different servers.

Schema updates are also handled much more reliably.

samba-tool drs replicate with new options

samba-tool drs replicate got two new options:

  • The option '--local-online' will do the DsReplicaSync() via IRPC to the local dreplsrv service.
  • The option '--async-op' will add DRSUAPI_DRS_ASYNC_OP to the DsReplicaSync(), which won't wait for the replication result.

replPropertyMetaData Changes

During the development of the DRS replication, tests showed that Samba stores the replPropertyMetaData object incorrectly. To address this, be aware that dbcheck will now detect and offer to fix all objects in the domain for this error.

Linked attributes on deleted objects

In Active Directory, an object that has been tombstoned or recycled has no linked attributes. However, Samba incorrectly maintained such links, slowing replication and run-time performance. dbcheck now offers to remove such links, and they are no longer kept after the object is tombstoned or recycled.

Improved AD DC performance

Many other improvements have been made to our LDAP database layer in the AD DC, to improve performance, both during samba-tool domain provision and at runtime.

Other dbcheck improvements

  • samba-tool dbcheck can now find and fix a missing or corrupted 'deleted objects' container.
  • BUG 11433: samba-dbcheck no longer offers to resort auxiliary class values in objectClass as these were then re-sorted at the next dbcheck indefinitely.

Tombstone Reanimation

Samba now supports tombstone reanimation, a feature in the AD DC allowing tombstones, that is objects which have been deleted, to be restored with the original SID and GUID still in place.

Multiple DNS Forwarders on the AD DC

Multiple DNS forwarders are now supported on the AD DC, allowing samba to fall back between two different DNS servers for forwarded queries.

Password quality plugin support in the AD DC

The check password script now operates correctly in the AD DC (this was silently ignored in past releases)

pwdLastSet is now correctly honoured

BUG 9654: the pwdLastSet attribute is now correctly handled (this previously permitted passwords that next expire).

net ads dns unregister

It is now possible to remove the DNS entries created with 'net ads register' with the matching 'net ads unregister' command.

Samba-tool improvements

Running samba-tool on the command line should now be a lot snappier. The tool now only loads the code specific to the subcommand that you wish to run.

SMB 2.1 Leases enabled by default=

Leasing is an SMB 2.1 (and higher) feature which allows clients to aggressively cache files locally above and beyond the caching allowed by SMB 1 oplocks. This feature was disabled in previous releases, but the SMB2 leasing code is now considered mature and stable enough to be enabled by default.

Open File Description (OFD) Locks

On systems that support them (currently only Linux), the fileserver now uses Open File Description (OFD) locks instead of POSIX locks to implement client byte range locks. As these locks are associated with a specific file descriptor on a file this allows more efficient use when multiple descriptors having file locks are opened onto the same file. An internal tunable "smbd:force process locks = true" may be used to turn off OFD locks if there appear to be problems with them.

Password sync as active directory domain controller

The new commands 'samba-tool user getpassword' and 'samba-tool user syncpasswords' provide access and syncing of various password fields.

If compiled with GPGME support (--with-gpgme) it's possible to store cleartext passwords in a PGP/OpenGPG encrypted form by configuring the new "password hash gpg key ids" option. This requires gpgme devel and python packages to be installed (e.g. libgpgme11-dev and python-gpgme on debian/ubuntu).

Python crypto requirements

Some samba-tool subcommands require python-crypto and/or python-m2crypto packages to be installed.

SmartCard/PKINIT improvements

"samba-tool user create" accepts --smartcard-required and "samba-tool user setpassword" accepts --smartcard-required and --clear-smartcard-required.

Specifying --smartcard-required results in the UF_SMARTCARD_REQUIRED flags being set in the userAccountControl attribute. At the same time the account password is reset to a random NTHASH value.

Interactive password logons are rejected, if the UF_SMARTCARD_REQUIRED bit is set in the userAccountControl attribute of a user.

When doing a PKINIT based kerberos logon the KDC adds the required PAC_CREDENTIAL_INFO element to the authorization data. That means the NTHASH is shared between the PKINIT based client and the domain controller, which allows the client to do NTLM based authentication on behalf of the user. It also allows on offline logon using a smartcard to work on Windows clients.

CTDB changes

  • New improved ctdb tool
ctdb tool has been completely rewritten using new client API.
Usage messages are much improved.
  • Sample CTDB configuration file is installed as ctdbd.conf.
  • The use of real-time scheduling when taking locks has been narrowed to limit potential performance impacts on nodes
  • CTDB_RECOVERY_LOCK now supports specification of an external helper to take and hold the recovery lock
See the RECOVERY LOCK section in ctdb(7) for details. Documentation for writing helpers is provided in doc/cluster_mutex_helper.txt.
  • "ctdb natgwlist" has been replaced by a top level "ctdb natgw" command that has "master", "list" and "status" subcommands
  • The onnode command no longer supports the "recmaster", "lvs" and "natgw" node specifications
  • Faster resetting of TCP connections to public IP addresses during failover
  • Tunables MaxRedirectCount, ReclockPingPeriod, DeferredRebalanceOnNodeAdd are now obsolete/ignored
  • "ctdb listvars" now lists all variables, including the first one
  • "ctdb xpnn", "ctdb rebalanceip" and "ctdb rebalancenode" have been removed
These are not needed because "ctdb reloadips" should do the correct rebalancing.
  • Output for the following commands has been simplified:
ctdb getdbseqnum
ctdb getdebug
ctdb getmonmode
ctdb getpid
ctdb getreclock
ctdb getpid
ctdb pnn
These now simply print the requested output with no preamble. This means that scripts no longer need to strip part of the output.
"ctdb getreclock" now prints nothing when the recovery lock is not set.
  • Output for the following commands has been improved:
ctdb setdebug
ctdb uptime
  • "ctdb process-exists" has been updated to only take a PID argument
The PNN can be specified with -n <PNN>. Output also cleaned up.
  • LVS support has been reworked - related commands and configuration variables have changed
"ctdb lvsmaster" and "ctdb lvs" have been replaced by a top level
"ctdb lvs" command that has "master", "list" and "status" subcommands.
See the LVS sections in ctdb(7) and ctdbd.conf(5) for details, including configuration changes.
  • Improved sample NFS Ganesha call-out

New shadow_copy2 options


With growing number of snapshots file-systems need some mechanism to differentiate one set of snapshots from other, e.g. monthly, weekly, manual, special events, etc. Therefore these file-systems provide different ways to tag snapshots, e.g. provide a configurable way to name snapshots, which is not just based on time. With only shadow:format it is very difficult to filter these snapshots. With this optional parameter, one can specify a variable prefix component for names of the snapshot directories in the file-system. If this parameter is set, together with the shadow:format and shadow:delimiter parameters it determines the possible names of snapshot directories in the file-system. The option only supports Basic Regular Expression (BRE).


This optional parameter is used as a delimiter between shadow:snapprefix and shadow:format This parameter is used only when shadow:snapprefix is set.
Default: shadow:delimiter = "_GMT"


only user and username parameters

These two parameters have long been deprecated and superseded by "valid users" and "invalid users".

smb.conf changes

 Parameter Name                Description             Default
 --------------                -----------             -------
 kccsrv:samba_kcc              Changed default         yes
 ntlm auth                     Changed default         no
 only user                     Removed
 password hash gpg key ids     New
 shadow:snapprefix             New
 shadow:delimiter              New                     _GMT
 smb2 leases                   Changed default         yes
 username                      Removed


Currently none.