In general, it is not mandatory to use a “system DSN” instead of “user DSN”, while registering a DSN that points to the Denodo Virtual DataPort server. However, the “system DSN” has an advantage when compare to “user DSN” as explained below,
I will use either of the DSN’s based on my necessity/requirement.
1. If my requirement is to provide **DSN** access for all the users residing in the same machine, then I will create a **system DSN**. Upon successful registration, all the users located in the system can access the Denodo server via ODBC connection. Also, make a note that only the **Local administrator** of the machine can register a **system DSN**.
2. Otherwise, if my need is to provide **DSN** access only for a particular user, then I will create a **user DSN** with the same user account that will connect to the Denodo. By this way, only the respective user will be able to establish an ODBC connection to Denodo.
For more information regarding the DSN’s, have a look at the below documentations.
* [**Register a Data Source (DSN) on UnixODBC**](https://community.denodo.com/docs/html/browse/8.0/en/vdp/developer/access_through_odbc/configuration_of_the_odbc_driver_in_linux_and_other_unix/configuration_of_the_odbc_driver_in_linux_and_other_unix#register-a-data-source-dsn-on-unixodbc)
* [**Set Up a DSN on Windows**](https://community.denodo.com/docs/html/browse/8.0/en/vdp/developer/access_through_odbc/configuration_of_the_odbc_driver_on_windows/configuration_of_the_odbc_driver_on_windows#set-up-a-dsn-on-windows)
* [**Backward Compatibility of the ODBC Driver**](https://community.denodo.com/docs/html/browse/8.0/en/vdp/developer/access_through_odbc/access_through_odbc#backward-compatibility-of-the-odbc-driver)
* [**How to access to VDP from OBIEE via ODBC in Linux**](https://community.denodo.com/kb/en/view/document/How%20to%20access%20to%20VDP%20from%20OBIEE%20via%20ODBC%20in%20Linux#h.zg5lqysh8qi2)
Hope this helps!