From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Ledford Subject: Re: [PATCH] Ghost devices being reported with AIC7XXX version 6.2.6 Date: Thu, 31 Oct 2002 15:07:58 -0500 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <20021031200758.GB30047@redhat.com> References: <20021031170337.GO574@lapi0061> <798370000.1036087399@aslan.btc.adaptec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <798370000.1036087399@aslan.btc.adaptec.com> List-Id: linux-scsi@vger.kernel.org To: "Justin T. Gibbs" Cc: Mike Brown , bferjul@emc.com, jkrasner@emc.com, conway_heather@emc.com, linux-scsi@vger.kernel.org On Thu, Oct 31, 2002 at 11:03:19AM -0700, Justin T. Gibbs wrote: > > Justin can you change AHC_NUM_LUNS to 32 or suggest an alternative fix? > > The aic7xxx driver is not at fault and so should not be changed. > The aic7xxx driver really does support all 64 luns. In my opinion, > there are three problems here: > > 1) The Symetrix should treat a non-zero LUNTAR bit as an invalid > selection. This would prevent these higher luns from showing up > as valid devices. > > 2) Linux should never use more than 5 bits of lun for a device that > reports itself as SCSI-2. If the lun is larger than what will > fit in 3 bits, byte 1 of the CDB should not be altered even if > the device is SCSI2. The whole "support more than 8 luns on SCSI-2 devices" is a hack anyway, I would be more likely to just remove it instead of changing other things. > 3) Linux should be using the Report Luns command to determine how > many luns are on a device and at what locations. This might > even allow you to never probe more than 8 luns on a SCSI 2 > device unless they support this command. Does the Symetrix support > it? Going beyond 8 luns on a SCSI2 device is really a hack > otherwise. We currently only do report luns on SCSI-3 devices. I didn't think this was a supported command on SCSI-2, but I hadn't checked the spec recently...hmmm...nope, not supported in SCSI-2, so using report luns on SCSI-2 devices is just as much a hack as going above lun 7 on SCSI-2 devices without specific knowledge of transfer interconnect. > -- > Justin > - > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Doug Ledford 919-754-3700 x44233 Red Hat, Inc. 1801 Varsity Dr. Raleigh, NC 27606