When sending a Knowledge Base to an instance of GeneXus Server, GXServer tries to connect to the default instance of SQL installed on the same machine where the server is running. To connect to that instance it uses 'Trusted Connection' which means the ASPNET account will have to have permissions to create data bases on that SQL Server.
If you'd like to change any of that you can use the knowledgebases.config file. This (xml) file is located under the GXserver installation directory and has the following tags:
<ConnectionInformation>
<IntegratedSecurity></IntegratedSecurity>
<UserId></UserId>
<Password></Password>
<ServerInstance></ServerInstance>
<Directory></Directory>
<DataLocation></DataLocation>
</ConnectionInformation>
IntegratedSecurity - Values “true/false” depending on integrated security is used or not. If no value is specified “true” is assumed.
UserId - if Integrated security is set to “false” a user name must be included here.
Password - if integrated security is set to "false” the user password must be included here.
ServerInstance - SQL Server instance name where the KBs will be hosted.
Tip: if ServerInstance value starts with "." (dot) it will be interpreted as "local server" and the KB MDF file will be created in the KB directory instead of SQL Server Instance default path.
Directory - Directory where the Knowledge Base will be created. If no value is specified “catalog” folder under GXServer installation folder is used.
DataLocation - The folder where SQL Server must saves the mdf and ldf files when creating a Knowledge Base (via Publish KB to server) - Available from X Evolution 1 Upgrade 4
Keep in mind that this info is ONLY used when the server gets a Send Knowledge Base to GeneXus Server request.