Every object you want to use S-Drive with must have an associated S-Drive File object with either a master-detail relationship or lookup relationship where the file object is the child.
You can create your file object using a spreadsheet and following these instructions.
Once your file object has been created, see Configuring Custom S-Drive file object on Lightning Page or Classic Override Page for S-Drive.
If you want to create a trigger to prevent a record from being deleted if there are files attached to it, see (Optional) Create a Before Delete Trigger for Custom Object
If you want to track File Activities on this file object (see File Activities and S-Drive Reports ), you must first create a lookup relationship in File Activity object with for this S-Drive file object. You can create the relationship from Setup > Objects > File Activity > Scrolling to "Custom Fields & Relationships" section > Clicking on "New" button > Select "Lookup Relationship" and select your new file object as "Related To" from the picklist provided.
When creating a custom file object, do not give it the same API name as the objects in the S-Drive Managed package (AccountFile, ContactFile, CaseFile, OpportunityFile, Lead_File). This will cause errors until the API name is changed.