Problem: SMB Shares Inaccessible After UCS Update and Migration

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TLDR

• Problem: SMB shares failed after renaming network adapters.
• Cause: Network adapter changes were manually written to /etc/univention/base.conf but a ucr commit was not run.
• Effect: The missing ucr commit meant the change wasn’t applied to smb.conf, so Samba still pointed to the old, non-existent interface.
• Solution: Run ucr commit on the affected server, then reboot.

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Problem

After a domain-wide update to Univention Corporate Server (UCS) 5.2 and a migration of all virtual machines, many Samba (SMB) shares became inaccessible. The network adapters’ names were changed during the migration. The UCS domain consists of a Primary Directory Node, two Backup Directory Nodes, and several Replica Directory Nodes. Each Replica Directory Node hosts different SMB shares that school computers and other clients need to access. However, access is only possible on two of these servers, with the rest denying all connections.

Root Cause

The issue stemmed from an incomplete configuration update. After the migration and network adapter renaming (done manually in /etc/univention/base.conf), the ucr commit command was only applied to the interfaces/* Unified Configuration Registry (UCR) scope. This meant that while the samba/interface UCR variable still correctly referenced the interfaces/primary value, this change was not written to the smb.conf file. As a result, the Samba configuration continued to use the old, now non-existent, network interface name, preventing it from binding to the correct network adapter and serving the shares.

Solution

To resolve this problem, you need to re-commit the entire UCR and then restart the relevant services. This forces the system to write all new configuration settings, including the correct network interface name for Samba, to their respective configuration files.

1. Commit the full UCR: Open a terminal on the affected Replica Directory Node and run the following command to commit all UCR changes.

   ucr commit
   

   This command ensures that all UCR variables are properly written to their respective configuration files.

2. Restart the system: After committing the changes, a full system reboot is necessary to apply the new network and Samba configurations.

   reboot
   

   Alternatively, if a full reboot isn’t feasible, you can try restarting the Samba service specifically, but a reboot is the most reliable way to ensure all dependencies are correctly initialized.