by Marc Luther Capulong on WordPress.org
This plugin allows the admin to set a storage limit (in MB) for each users based on their role. If the user attempts to upload a file, the plugin will …

Plugin settings Page. Example of setting a 10MB limit to the Administrator Role
This plugin allows the admin to set a storage limit (in MB) for each users based on their role. If the user attempts to upload a file, the plugin will check if the user meets the maximum amount of storage space and will throw an error.
Error messages can be customized by using the ‘rbsl_sl_error_message’ filter.
Initially, values are set as unlimited. Which means that all users will have unlimited storage space.