Hi All, Thanks Dr. Hannes Reinecke. After read some docs, I found out this information about the WWID: - Its origin is the VPD Pages; - It's a NAA (Network Address Authority) identifier; - As a NAA identifier it is unique because its format is: 3 + 6(from NAA 6) + IEEE Company_id + Vendor Specific Identifier + Vendor Specific Identifier Extension + == concatenated Please, if it is not correct tell me. Thanks and Regards, Nascimento <div class="gmail_quote">On Mon, May 3, 2010 at 8:12 AM, Hannes Reinecke <<a href="mailto:hare@suse.de">hare@suse.de</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> <div class="im">Rodrigo Nascimento wrote: > Hi All, > > How the WWID from dm-mp is generated? I can image that it use serial > number of the disk, but how it is really generated? > </div>It is using the SCSI Inquiry VPD pages; page 0x83 or, failing that, path 0x80. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage <a href="mailto:hare@suse.de">hare@suse.de</a> +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Markus Rex, HRB 16746 (AG Nürnberg) -- dm-devel mailing list <a href="mailto:dm-devel@redhat.com">dm-devel@redhat.com</a> <a href="https://www.redhat.com/mailman/listinfo/dm-devel" target="_blank">https://www.redhat.com/mailman/listinfo/dm-devel</a> </blockquote></div> -- Rodrigo Nascimento Storage System Engineer (13) 8805-5892 <a href="http://stortech.wordpress.com">http://stortech.wordpress.com</a>