From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Vasquez Subject: Re: Number of devices that SCSI can support Date: Wed, 9 Jan 2008 07:49:33 -0800 Message-ID: <20080109154933.GC29564@plap3.qlogic.org> References: <404714.86520.qm@web43145.mail.sp1.yahoo.com> <20080109022233.GM16309@parisc-linux.org> <1199891152.3493.6.camel@localhost.localdomain> <20080109153601.GR16309@parisc-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from avexch1.qlogic.com ([198.70.193.115]:14603 "EHLO avexch1.qlogic.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751260AbYAIPtj (ORCPT ); Wed, 9 Jan 2008 10:49:39 -0500 Content-Disposition: inline In-Reply-To: <20080109153601.GR16309@parisc-linux.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Vinay Venkataraghavan Cc: James Bottomley , linux-scsi@vger.kernel.org, Matthew Wilcox On Wed, 09 Jan 2008, Matthew Wilcox wrote: > On Wed, Jan 09, 2008 at 09:05:52AM -0600, James Bottomley wrote: > > On Tue, 2008-01-08 at 19:22 -0700, Matthew Wilcox wrote: > > > On Tue, Jan 08, 2008 at 04:55:46PM -0800, Vinay Venkataraghavan wrote: > > > > Is there a limit on the number of devices that SCSI supports. In other words, I have a QLogic HBA card, and I am connecting to a SAN which has 64 targets. > > > > > > I've personally had over five hundred LUNs. You shouldn't be hitting a > > > limit here. > > > > I believe the largest test that's been run was the old OSDL CGL > > workgroup ... they went up to 4096. > > > > However, LUN support depends on the driver and HBA parameters as well > > (some choose to have arbitrary limits). > > I was using a qlogic HBA for my tests, so I don't think this is the > problem -- although the original poster claims to have 64 targets, and I > had only one target with 128 luns (attached 4 times). > > -- > Intel are signing my paycheques ... these opinions are still mine > "Bill, look, we understand that you're interested in selling us this > operating system, but compare it to ours. We can't possibly take such > a retrograde step." Not sure what's going on as well, perhaps some logs could help... But the inbox qla2xxx driver in RHEL4 set's an HBA's scsi_host->max_id count to 512 (also verified with several test rings), so there shouldn't be a problem handling 64 distinct targets (FC ports).