Thread:Project:Support desk/Is it possible to set a separate url for thumbs images?/reply

Sure :) You can use $wgUploadStashScalerBaseUrl to define a remote base for thumbnailing. Here the description of this value from DefaultSettings.php:

To enable remote on-demand scaling, set this to the thumbnail base URL. Full thumbnail URL will be like $wgUploadStashScalerBaseUrl/e/e6/Foo.jpg/123px-Foo.jpg where 'e6' are the first two characters of the MD5 hash of the file name. If $wgUploadStashScalerBaseUrl is set to false, thumbs are rendered locally as needed.