Does this mean the model weights are stored on the clearml-server file system?

By default they are just logged (i.e. the local path is stored, but the file is not uploaded). If you want to automatically store the model, pass output_uri=True to the Task.init , or any object store / shared folder (e.g. output_uri=' s3://bucket/folder ' ). ClearML will automatically create a subfolder for the Task, and upload all models/artifacts to it.
task = Task.init(project_name='examples', task_name='ignite', output_uri=True)(Upload to the file server)