Yes. It is possible. But you must have on s4 smb.conf and tdb's from s3 -- View this message in context: http://samba.2283325.n4.nabble.com/Upgrade-from-S3-to-a-Samba4-DC-tp3742504p3796498.html Sent from the Samba - samba-technical mailing list archive at Nabble.com.