The ILS drivers serve two main purposes:
1.) They provide real-time status of items (i.e. is it on shelf or checked out?)
2.) They provide access to patron information (user profiles, fines, holds, etc.)
If you have your driver configured correctly, you should see call numbers and availability statuses as part of your search results. If you are not seeing the correct call numbers, you might have to adjust the way call numbers are loaded in the getHolding method of web/Drivers/Koha.php.
The ILS driver only deals with real-time communication with the ILS. It does NOT automatically import records for you. In order to keep VuFind’s index up to date, you need to set up a process to automatically export MARC records from your ILS and load them into VuFind using the import-marc.sh script. This is completely independent from the driver.
I hope this is helpful – please let me know if you still have questions or problems.