Howto: Use automated KCC with Samba

Howto

Use Samba kcc for samba replication.

Environment

In some Domains you have multiple sites with different connection types. For full replication some of these connections might be to slow or to expensive.

You have configured your domain according to this article (outdated).
Further information:

root@master:~# ucr search kcc
samba4/kccsrv/samba_kcc: <empty>
 If this variable is set to 'yes', Samba/AD uses the new implementation of the KCC, which supports sparse network replication. If the variable is unset, the the older full mesh replication is used.

Solution

Step 1

Create and join additional UCS servers by configuring sites as shown in the article.

Step 2

Allow traffic between all sites. Samba will figure out the latency of the links an disable the slow ones with the kcc algorithm. Do not filter any packages by your firewall.

Step 3

Enable kcc support for Samba on ALL samba domain controllers (DCs):

root@master:~# ucr set samba4/kccsrv/samba_kcc=yes
root@master:~# /etc/init.d/samba restart

Step 4

Verify the settings with samba-tool:

root@master:~# samba-tool drs showrepl
root@master:~# samba-tool drs kcc