If you want to change the main database directory in the Pro Admin version there are a few things you have to prepare.

I want to change from the original directory to a new one. Here I'm going to use a sub folder on my desktop. My original database folder is in /Library/VServer_x64/databases. This is the top level library and not the user library:Database directory in Valentina Server

I only created a new folder on the desktop:

New directory for Valentina Server

The directories are listed in Status -> Directories:Original directory in Server Management

Clicking on the folder icon for Valentina Databases gives me a warning:

Warning when changing directories

To make sure that everything is okay I click on Cancel for now.

There is only one connection for the UserGroups database. It's currently not possible to remove the connection:

Checking connections

If a Mail Archiver archive is open remove the connection.

In Databases I make sure that the Mail Archiver database is unregistered. It's not possible to unregister the UserGroups database:

Making sure that archives are not registered

Now I make a copy of the databases in the new directory:

Copying databases to new directory

Finally I can change the database directory to the new one:

Restart required after changing directory

Mail Archiver tells me that a restart of Valentina Server is required. I click on the button with the white triangle above the logout button. I get back to the login screen:

Log in again

After logging back in I can see that the directory is now good to use:

Directory changed successfully

I can register the Mail Archiver database again:

Database was registered

I can now logout.

In the Setup I can connect again to my archive:

Connecting in Setup

And the archive opens from the new directory:

Archive opened from new directory