Problem with character size in username

Hello guys!

I approved the UCS for use here in the company. At most 100 users, but I found a problem with some of them.
Here we have already used samba 4 and we had no problems with the size of the login (username). When I migrated some of them, I found a barrier with a maximum size of 20 characters for the username. Is it possible to disable this or put some record in Univention so that you ignore this information?

Here all my systems and e-mail are connected to my samba 4 LDAP and will be migrated to UCS.

Thanks in advance

May you will find the answer in this bug-report dated in 2017:
If Windows clients are used:

because the MS docs say that the samaccountname (aka “Pre Windows-2000 Logon Name”) “must be 20 characters or less to support earlier clients”. If this would be an RFC, nobody would say, “Ok, it says must, but I don’t have that use case”.

found here:


I can do it another way. using samba-tool. it accepts more than 20 characters.