From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gal Rosen Subject: Re: SCSI device rescan, detection of disconnected device, or switched devices. Date: Thu, 31 Jul 2008 19:09:31 +0300 Message-ID: <1217520571.6768.14.camel@galr-linux.storwiz.com> References: <1217248348.4133.51.camel@galr-linux> <488DC55C.2050603@s5r6.in-berlin.de> <1217487434.25491.34.camel@galr-linux> <4891792C.6020304@s5r6.in-berlin.de> <1217504895.25491.69.camel@galr-linux> <1217513749.3333.7.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail.storwize.com ([62.90.10.208]:22772 "EHLO swdc2.storwiz.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750828AbYGaQJd convert rfc822-to-8bit (ORCPT ); Thu, 31 Jul 2008 12:09:33 -0400 In-Reply-To: <1217513749.3333.7.camel@localhost.localdomain> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: Stefan Richter , linux-scsi@vger.kernel.org On Thu, 2008-07-31 at 09:15 -0500, James Bottomley wrote: > Oh ... you're not really talking about hotplug, which is why everyone= is > confused. Hotplug is when you add or remove something from the bus. > What you've done is reconfigure the array. >=20 > Most of the hotplug we do depends on the transport model (because wha= t's > on the transport is changing). Array reconfiguration has no hotplug > event because SAM-3 has no real way of passing the information > asynchronously. The best it can do is Unit Attention/reported luns d= ata > has changed (asc=3D0x3f/ascq=3D0xe) on the next command. >=20 > The problem is that there's no way to process the event correctly eve= n > when we get it. All we can do is issue another report LUNS command a= nd > compare. However, just because it looks like a single LUN disappeare= d > doesn't mean the others weren't permuted or altered in some way (whic= h > data we cannot get). >=20 =EF=BB=BFWhy? if I keep a mapping between sg devices and device id (Inq= uiry page 0x83) then I have all the data. Gal. > So ... this event is manual intervention required because you have to > tell SCSI what you did to the array, it can't work it out for itself. >=20 > James >=20 >=20 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html