Samba 4.3 Features added/changed

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Samba 4.3.0-RC2

Release Notes for Samba 4.2.0-RC2
August 4, 2015

This is the second release candidate of Samba 4.3.

This is the second release candidate of Samba 4.3. 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 4.3 will be the next version of the Samba suite.


Nothing special.



The logging code now supports logging to multiple backends. In addition to the previously available syslog and file backends, the backends for logging to the systemd-journal, lttng and gpfs have been added. Please consult the section for the 'logging' parameter in the smb.conf manpage for details.


Support for Apple's Spotlight has been added by integrating with Gnome Tracker.

For detailed instructions how to build and setup Samba for Spotlight, please see Spotlight here.

New FileChangeNotify subsystem

Samba now contains a new subsystem to do FileChangeNotify. The previous system used a central database, notify_index.tdb, to store all notification requests. In particular in a cluster this turned out to be a major bottleneck, because some hot records need to be bounced back and forth between nodes on every change event like a new created file.

The new FileChangeNotify subsystem works with a central daemon per node. Every FileChangeNotify request and every event are handled by an asynchronous message from smbd to the notify daemon. The notify daemon maintains a database of all FileChangeNotify requests in memory and will distribute the notify events accordingly. This database is asynchronously distributed in the cluster by the notify daemons.

The notify daemon is supposed to scale a lot better than the previous implementation. The functional advantage is cross-node kernel change notify: Files created via NFS will be seen by SMB clients on other nodes per FileChangeNotify, despite the fact that popular cluster file systems do not offer cross-node inotify.

Two changes to the configuration were required for this new subsystem:

The parameters "change notify" and "kernel change notify" are not per-share anymore but must be set globally. So it is no longer possible to enable or disable notify per share, the notify daemon has no notion of a share, it only works on absolute paths.

New SMB profiling code

The code for SMB (SMB1, SMB2 and SMB3) profiling uses a tdb instead of sysv IPC shared memory. This avoids performance problems and NUMA effects. The profile stats are a bit more detailed than before.

Improved DCERPC man in the middle detection for kerberos

The gssapi based kerberos backends for gensec have support for DCERPC header signing when using DCERPC_AUTH_LEVEL_PRIVACY.

SMB signing required in winbindd by default

The effective value for "client signing" is required by default for winbindd, if the primary domain uses active directory.

Experimental NTDB was removed

The experimental NTDB library introduced in Samba 4.0 has been removed again.

Improved support for trusted domains (as AD DC)

The support for trusted domains/forests has improved a lot.

samba-tool got "domain trust" subcommands to manage trusts:

 create      - Create a domain or forest trust.
 delete      - Delete a domain trust.
 list        - List domain trusts.
 namespaces  - Manage forest trust namespaces.
 show        - Show trusted domain details.
 validate    - Validate a domain trust.

External trusts between individual domains work in both ways (inbound and outbound). The same applies to root domains of a forest trust. The transitive routing into the other forest is fully functional for kerberos, but not yet supported for NTLMSSP.

While a lot of things are working fine, there are currently a few limitations:

  • Both sides of the trust need to fully trust each other!
  • No SID filtering rules are applied at all!
  • This means DCs of domain A can grant domain admin rights in domain B.
  • It's not possible to add users/groups of a trusted domain into domain groups.

SMB 3.1.1 supported

Both client and server have support for SMB 3.1.1 now.

This is the dialect introduced with Windows 10, it improves the secure negotiation of SMB dialects and features.

New smbclient subcommands

  • Query a directory for change notifications: notify <dir name>
  • Server side copy: scopy <source filename> <destination filename>

New rpcclient subcommands

 netshareenumall 	- Enumerate all shares
 netsharegetinfo 	- Get Share Info
 netsharesetinfo 	- Set Share Info
 netsharesetdfsflags	- Set DFS flags
 netfileenum		- Enumerate open files
 netnamevalidate	- Validate sharename
 netfilegetsec		- Get File security
 netsessdel		- Delete Session
 netsessenum		- Enumerate Sessions
 netdiskenum		- Enumerate Disks
 netconnenum		- Enumerate Connections
 netshareadd		- Add share
 netsharedel		- Delete share

New modules

 idmap_script 		- see 'man 8 idmap_script'
 vfs_unityed_media	- see 'man 8 vfs_unityed_media'
 vfs_shell_snap	- see 'man 8 vfs_shell_snap'

New sparsely connected replia graph (Improved KCC)

The Knowledge Consistency Checker (KCC) maintains a replication graph for DCs across an AD network. The existing Samba KCC uses a fully connected graph, so that each DC replicates from all the others, which does not scale well with large networks. In 4.3 there is an experimental new KCC that creates a sparsely connected replication graph and closely follows Microsoft's specification. It is turned off by default. To use the new KCC, set "kccsrv:samba_kcc=true" in smb.conf and let us know how it goes. You should consider doing this if you are making a large new network. For small networks there is little benefit and you can always switch over at a later date.

Configurable TLS protocol support, with better defaults

The "tls priority" option can be used to change the supported TLS protocols. The default is to disable SSLv3, which is no longer considered secure.


smb.conf changes

 Parameter Name		Description		Default
 logging			New			(empty)
 msdfs shuffle referrals	New			no
 smbd profiling level		New			off
 spotlight			New			no
 tls priority			New 			NORMAL:-VERS-SSL3.0
 use ntdb			Removed
 change notify			Changed to [global]
 kernel change notify		Changed to [global]
 client max protocol		Changed	default		SMB3_11
 server max protocol		Changed default		SMB3_11

Removed modules

vfs_notify_fam - see section 'New FileChangeNotify subsystem'.


Currently none.


  • Jeremy Allison <>
  • Björn Baumbach <>
  • Justin Maggard <>
  • BUG #11320: "force group" with local group not working
  • Martin Schwenke <