Hi, I'm going to attempt to upgrade our PDC from 2.2.8a to 3.0.10 sometime very soon. This is fairly mission critical as our 300+ clients rely on it for authentication. After reading around I propose the following steps to make the upgrade transparent (at least for the end users) : 1) install samba 3 alongside samba 2 on the PDC (seperate path etc). 2) run the samba 3 net getlocalsid <domain> whilst still running 2.2 to get the domains SID 3) copy the smb.conf and smbpasswd from the 2.2 tree to the 3 tree (am content to run with the old smbpasswd backend for now, migration to ldap will come later) 4) edit smb.conf to reflect changes in version 3 (notably the domain group mappings) 5) stop 2.2 6) start 3 7) use net setlocalsid to set the Samba 3 SID to the old 2.2 one. 8) Cross fingers :) I'm hoping this will allow machines to act as part of the domain without having to rejoin and also users to login etc and have access to their profiles etc (i.e their user SID / RID has been migrated successfully). In short not noticing any difference other than (hopefully) an increase in performance. Can anyone comment on these steps? am I missing something critical? does it seem in order? has anyone else done this the same way and had success? Apologies if this has been beaten to death here but its difficult finding a definitive list of things needed to be done. To be honest I'm slightly dissapointed it's not covered step by step in depth by the official samba howto upgrade section. It seems like a procedure that would be very common. Thanks for any help you can give, Kev