1. Backend:
    (1)API definition:
    POST /storagepools/isos/storagevolumes/upload {'file': fileobject} -- This is from backend view, as cherrypy's embedded support wraps fileobject.
    REF:http://docs.cherrypy.org/en/latest/pkg/cherrypy.tutorial.html?highlight=upload

   (2) implementation:
        We can get the file handler from cherrypy's embedded scheme, and use it to read and write to a local file, ref:
            https://groups.google.com/forum/#!topic/cherrypy-users/xGvxBGgQ90k
       The only thing we need to concern at backend is the file size, cherrypy demo has proposed a example leverage cgi lib:
           http://tools.cherrypy.org/wiki/DirectToDiskFileUpload
       

2.  For UI, we need to supply user with a form which input type is 'file', or we construct formdata in ajax(for IE only supported in IE10+):
    REF:
       http://stackoverflow.com/questions/6974684/how-to-send-formdata-objects-with-ajax-requests-in-jquery

3. To support the progress bar in UI, we can utilize resumable js: http://github.com/23/resumable.js