In this paper we show the capabilities of the Large Volume Detector (INFN
Gran Sasso National Laboratory) to identify a neutrino burst associated to a
supernova explosion, in the absence of an "external trigger", e.g., an optical
observation. We describe how the detector trigger and event selection have been
optimized for this purpose, and we detail the algorithm used for the on-line
burst recognition. The on-line sensitivity of the detector is defined and
discussed in terms of supernova distance and electron anti-neutrino intensity
at the source.Comment: Accepted for pubblication on Astroparticle Physics. 13 pages, 10
figure