From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH] scsi_transport_spi: Export host width and HBA id Date: Fri, 03 Jun 2011 07:59:22 +0200 Message-ID: <4DE8783A.9010801@suse.de> References: <201106011318.p51DImMr003035@pentland.suse.de> <1306940171.11897.52.camel@mulgrave.site> <4DE65408.2020502@suse.de> <4DE6579F.8080402@interlog.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:57069 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751110Ab1FCF7Y (ORCPT ); Fri, 3 Jun 2011 01:59:24 -0400 In-Reply-To: <4DE6579F.8080402@interlog.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: dgilbert@interlog.com Cc: James Bottomley , James Bottomley , linux-scsi@vger.kernel.org On 06/01/2011 05:15 PM, Douglas Gilbert wrote: > On 11-06-01 11:00 AM, Hannes Reinecke wrote: >> On 06/01/2011 04:56 PM, James Bottomley wrote: >>> On Wed, 2011-06-01 at 15:18 +0200, Hannes Reinecke wrote: >>>> Currently it's impossible to find out if the host supports >>>> wide SCSI unless you're committed to trawl through syslog. >>>> And it's near impossible to find the actual HBA id, which >>>> is settable for some SCSI HBAs (like aic7xxx). >>>> So export them via sysfs. >>> >>> Um, that's what the the >>> >>> /sys/class/spi_transport/target/max_width >>> >>> parameter gives you, isn't it? >>> >>> max_width tells you if the HBA/device combination supports wide; >>> width >>> tells you if the device is using it. >>> >> Not quite. You'll only have that parameter if there is a target >> attached to the >> HBA. >> If there is none you still wouldn't know how far you should be >> scanning as there >> won't be any indicator in sysfs. >> >> In this case that's an ESX server emulating an sym53c8xx HBA. >> And disks attached to it on the fly. >> If you start up with no disks attached and attach a new disc >> to eg target ID 12 you're stuck. > > It is about time that VMware emulated SAS rather than SPI for > virtual storage. Then if something changes, ESX can emulate > a SAS Broadcast(Change) and then smarter SAS HBA drivers will > run their discover process and find the changes. > Hey, don't tell me. I'm fighting for years to get my megaraid SAS emulation into Qemu. And it took me about the same time to get VMWare to buy into the=20 idea of supporting VPD page 0x83. So I won't hold my breath there. And, btw, we'd need the hba_id anyway if we ever want to calculate=20 transport IDs on SCSI parallel devices :-). Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg GF: J. Hawn, J. Guild, F. Imend=C3=B6rffer, HRB 16746 (AG N=C3=BCrnberg= ) -- 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