I decided to write this long post because I hope it'll come useful to someone because this problem has made me crazy for nearly two days!!!! And the bad thing is that I have found virtually no documentation / solution / comments on the internet that have been helpful (apart from one!). I had to complete an upgrade of an active directory 2000 domain, made by 2 domain controller, to 2008 R2 version (always with 2 domain controller).
I prepare everything with adprep, I raise the the domain and forest level in 2000 native and when ready I even run dcpromo on the two new dc, everything ok, no error and after the servers restart active directory db is properly replicated as well as dns. Everything would seem to be ok…. but unfortunately it is not so.
Taking some additional tests to see if everything was properly synchronized I realize that both new dcs are not sharing the sysvol (and of course the netlogon share too as it is a sysvol subfolder).
I try to give a look in event viewer and I see this warning that always appears when you configure a new domain controller:
Normally this warning refers only to a temporary state while the new dc synchronizes sysvol but in my case it was stucked in this state and the sysvol was not shared….. and then I started to do some’ troubleshooting. First thing I noticed is that the two current 2000 dc did not synchronize their SYVOL each other from years… eh vabeh. I do inspections on dns, allright, names resolution is ok; I look at the event viewer on both win 2000 dc and there are no errors; file replication services are active, I try to restart them but nothing changes and on the 2000 dc the only events that I see are the stop and start of the service…. a little weird! On 2008R2 dc instead two warning appear that indicate that the server can not synchronize with the sysvol of the two 2000 dc.
I start searching on google, I find a lot of posts, reports of replication problems. Many of them relative to dns problems, many who simply forced a reset of the service by editing the registry key BurFlags: https://support.microsoft.com/en-us/kb/290762, others that linked back to this Microsoft KB for troubleshooting: https://msdn.microsoft.com/en-us/library/bb727056.aspx. Even following ALL (!!!) the tests I do not find a cause of the problem. I start watching the ntfrs service logs, on 2008R2 servers I find some errors: ERROR_ACCESS_DENIED (but "access denied to to what" is not clear) while on the 2000 servers from which they where trying to synchronize the sysvol there were two types of errors:
set DOMAIN SYSTEM VOLUME (SYSVOL SHARE) on parent SERVERNAME; WStatus: ERROR_NOT_FOUND
and
ERROR – Invalid Partner: AuthClient:SERVERNAME
Looking on google I have not found any useful tip, all were making reference as stated before on dns problems or KB microsoft little helpful in this case. After hours and hours in which I did not know what to do, I also tried to force frs replication on a static port (even if the servers were on the same subnet without firewall between them) but nothing…. But at least I saw that the service responded (although I had already had a confirmation about that with the command NTFRSUTL VERSION). Tried dozens of other solutions but without any results, I did not really know what to do….
SOLUTION (at the end…...)
After nearly two days of headache I found this page: http://www.skar.us/thepost/system_admin/product/microsoft/windows_server/active-directory/frs/w2k3sfrs-replication-sharing-problem/ where there were some errors that appeared in my logs and also claimed to have solved simply by adding a missing registry key, and in fact the day before I had noticed that the tree of the register of the NtFrs service (Computer->HKLM->System->CurrentControlSet->services->NtFrs->Parameters) was slightly different, on win 2000 the key was missing this key: “SysVol”. Ok let's try this too: I manually insert the key…. restart services….. wait a bit '…… I see new events appear in the event viewer of the 2000 dc…. IT WORKS!!!!!!!! Two days lost because of a registry key disappearance!!! I HATE USELESS MICROSOFT LOGS!!!!!!!
P.S.
On the second win 2000, that was not synchronized from years, and that still had some problems I had to launch a reset with the D2 value in BurFlags variable to fix things.