Migrate from UCS 4 to Microsoft AD 2019

[tacioandrade]

Good afternoon, I have an environment with Univention that started small with 1 site and 2 farms, but today I’m facing serious problems with it, all of a sudden the RPC stops working and it’s necessary to restart Univention to make it work again. all possible logs and I don’t find the cause of the problem.

The company administrator asked to see if there is any way to migrate UCS to Windows Server AD without losing users.

I would like to know if there is a way to do the Inverted Takeover, pulling the entire domain from UCS to Microsoft AD from Windows Server 2019.

Does anyone know if it’s possible? And if so, what would the process look like? Thank you in advance for your help, as I have no idea what to do, I even thought of scheduling via cron the domain controller reboot 2 or 4 times a day to see if the problem goes away, but I gave up for fear of corrupting some file and making it even worse the situation.

Before the process, I will try to update the UCS to 5.0, but I want to be prepared in case of failure to have a plan B.

[BenSommer]

Hi
maybe you have a hardware problem. Check the memory with memtest86 and your disks with a smart tool (apt-get install smartmontools)
https://help.ubuntu.com/community/Smartmontools

Best Ben

[tacioandrade]

It’s not a hardware problem, it’s running on a Proxmox with 18 more VMs and all working fine! I figured it was memory I increased to 8GB and 4 vcore, UCS doesn’t use today or 1/4 of it and even so the RPC problems continue to occur!
I’ve looked at practically all the logs, searched everywhere and didn’t find the problem, tried to restart the most diverse services, samba, winbind, kerberos, etc., it only comes back when I restart the UCS as a whole.
Then after some time (usually a few days, but it can be hours) every type of login in the domain stops working and when I open the GPMC.MSC it informs RPC error when loading the forest and does not open.
The customer is already stressed with this problem and I don’t know what to do anymore, so I’ll upgrade from 4.4 to 5.0 and if it doesn’t solve it, I’m already looking for a plan B to pull users, information and groups to an AD 2019.

[BenSommer]

Try to look here:

How to deal with s4-connector rejects

S4-Connector Rejects Rejects You can use the following command to have a look at the current S4-Connector replication status: univention-s4connector-list-rejected If you see rejected objects in the output it is recommended to have a look at the relevant log files to determine the reason for the reject. The relevant log file is /var/log/univention/connector-s4.log. UCS rejected refers to object modifications that have been detected in UCS/OpenLDAP and could not be synchronized to the Samba/AD …

Samba 4 Troubleshooting

Samba 4 Troubleshooting Guide DRS Replication samba-tool drs showrepl To get an overview of the current drs replication status you can use this command at every UCS Samba 4 DC which is joined to the domain: samba-tool drs showrepl Sitename\Servername DSA Options: 0x00000001 DSA object GUID: ffad9f19-0e90-457b-b733-469e4b2280a1 DSA invocationId: 908dbb52-12a6-47a2-ae03-1a71014cc4f4 ==== INBOUND NEIGHBORS ==== DC=domain,DC=base Sitename\Servername via RPC DSA object GUID: 397575b4-…

Re-Provisioning Samba4 on a DC Master

This article describes the re-provision of a Samba 4 DC Master. Please see this article if a UCS@school environment is used. Problem: Several Samba 4 data is either lost or corrupt The LDB-Data of Samba 4 (z.B. /var/lib/samba/private/sam.ldb) is corrupted/broken/lost and Samba 4 has to be re-provisioned. Solution: Samba 4 can be re-provisioned with the help of the existing LDAP data The following steps will describe the needed procedure: Note: Make sure that all of your groups/users have a …

In my case it was a problem with the s4 connector

Greetings Ben